THE 
Key to Sex Control THE 
Key to Sex Control 
OR 
The Cellular Determination 
of Sex and The Physiological 
Laws Which Govern Its Control 
BY 
percy john mcelrath, m.d. 
NEW YORK CITY 
PUBLISHED BY THE AUTHOR 
MDCCCCXI Copyrighted, 1911 
By Percy John McElrath, M.D. 
AU Rights Reserved PREFACE. 
The present volume is the outcome of several years of 
study and experiment in the broad field of cell-life. The 
author has long entertained the opinion that the beauti- 
ful axiom, The Universe is Governed by Law, applies 
not only to the suns and planets in their courses, but, 
with equal force and completeness, to the complex phe- 
nomena of the minute cells that combine to form the 
bodies of men and animals. He believes that the prob- 
lems of heredity, sex, and development, which so funda- 
mentally affect the human race and which have so long 
baffled investigators, are based on invariable natural 
laws, a proper knowledge of which will have a far-reach- 
ing effect on the future development of the human race. 
The famous aphorism of Socrates, " Know thyself," 
applies especially to man as a complex organism, and 
with peculiar force to his sacred sexual relations in the 
propagation of his species. False modesty has too long 
been the handmaid of ignorance in the most important 
and far-reaching duty of human life, and it is high time 
that the scientist should realize that the improvement 
and development of the race lie within his domain and 
that all other biological laws dwindle into insignificance 
in comparison with this great problem. 
5 6 
PREFACE. 
Before Intelligence, in the form of man, made its 
appearance on the earth, the evolution of life-forms had 
proceeded without apparent direction or reason; the 
multiplication and variation of species were stupendous. 
Most of these various forms are known to-day only as 
fossils in the graveyard of Evolution; many, however, 
have persisted and comprise the useful and useless ani- 
mals that inhabit the earth with man. Few, if any, new 
species have originated since Homo sapiens appeared on 
the scene, and many, doubtless, may attribute their 
extinction to his interference. As the descendants of 
this wonderful primate gradually extend their dominion 
over the earth, the face of the planet is changed in many 
respects, many of the forces of nature are harnessed to 
do man's bidding and even evolution itself is made, in 
some degree at least, to serve his wants. Many animals 
that are useless or malignant have been exterminated or 
greatly reduced in number and range; others that are 
useful to man have been protected, increased in number, 
and improved. 
Only within the last hundred years, however, have the 
great laws of natural selection and survival of the fittest 
been understood, with the result that man is beginning to 
supplement natural selection with intelligent selection. 
By proper selection and breeding, many fruits, grains, 
and vegetables have been greatly improved, new kinds 
have been produced and even useless plants have been 
changed into useful food plants. Animals have been 
domesticated and, by selection, have been improved and 
made to serve man in various ways. The work of such PREFACE. 
7 
men as Burbank, Gregon Mendel, Charles Darwin, and 
others is eloquent of a glorious future, in which man, 
brought to a full realization of the possibilities of in- 
telligent selection and breeding, will not only bend his 
energies to improve plants and animals, but will also 
undertake that greater and nobler work of improving 
the human species. 
While the prevention of breeding by the deformed, the 
criminal, and the degenerate may not be possible for 
centuries to come, it is possible to teach the people the 
fundamental facts and laws that govern the reproduction 
of the species and to publish, so that all may know, those 
conditions of health, nutrition, environment, and physi- 
cal fitness that control and determine this all-important 
phenomenon. There is no biological process that ap- 
proaches in importance that by means of which human 
life is propagated; and none about which greater igno- 
rance prevails. It concerns not only the continuance of 
the race on the planet, but, very largely, the character of 
the race. Consequently, every individual who expects 
to become a father or a mother should know, to the 
fullest extent, the anatomy of the parts concerned, the 
biological and physiological laws governing them, and, 
especially, the rules and circumstances under which the 
finest specimens of offspring may be produced. 
The author firmly believes that a full and complete 
knowledge of the conditions under which insemination, 
fertilization, and embryonic development take place will 
enable the scientist to solve the ultimate problems of 
inheritance and sex, which are acknowledged to be cell- 8 
PREFACE. 
problems. He offers the present volume, therefore, with 
the belief that it will be a material step toward the solu- 
tion of these problems and that it will stimulate others to 
take up this most important but neglected branch of 
research. At the present stage of his investigations, the 
author does not claim that sex-control can be rendered 
absolute, for conditions cannot always be made ideal, 
but he does assert that sex can be predetermined in a 
majority of cases in mammals, birds, fishes, and reptiles. 
Believing that Science will improve and perfect the 
human species, as it has improved other species, and with 
an abiding faith in the future of the race that has weighed 
suns and isolated cells, the author submits his work to 
the serious consideration of a candid world. 
Grateful appreciation is due to Lieut. Riley E. Scott 
for his aid in preparing the chapter on history. The 
illustrations, for the most part, are the work of Mr. 
F. A. Deck, whose efficient service has materially 
enhanced the value of the book. 
PERCY JOHN McELRATH, M.D., 
New York City, 
November, 1911. 
Residence, 
Bramwell, 
W. Va. CONTENTS. 
PAGE 
Preface . ... 5 
List of Illustrations . . . . . . .11 
CHAPTER I. 
Sex Control. Its History 13 
CHAPTER II. 
The Male Generative Organs. Their Embryonic De- 
velopment, Histology, Anatomy, and Physiology . 19 
CHAPTER III. 
The Female Generative Organs. Their Embryonic De- 
velopment, Histology, Anatomy, and Physiology . 42 
CHAPTER IV. 
The Spermatozoon. Its Development, Anatomy, His- 
tology, and its Role in Production of Life . . 79 
CHAPTER V. 
The Ovum. Its Development, Anatomy, Histology, and 
its ROle in Production of Life . . . .106 
CHAPTER VI. 
Menstruation. The Guide to Sex Control. Its Prob- 
able Cause. Its Variation in Different Races and 
Classes 123 
9 10 
CONTENTS. 
CHAPTER VII. 
PAGE 
The Process of'Insemination 145 
CHAPTER VIII. 
The Cellular Determination of Sex. The Direct Cause, 
and the Primary Laws Governing its Variation . 149 
CHAPTER IX. 
The Paternal and Maternal Secondary Laws which 
Govern the Variation of Sex 200 
CHAPTER X. 
Final Instructions. The Control of Sex in the Human 
Species. The Control of Sex in the Class Aves or 
Bird, Reptile and Fish Families 221 
Bibliography 227 
Index ........... 229 ILLUSTRATIONS. 
FIG. PAGE 
i. Enlarged View from the Front of the Left Wolffian Body 
before the Establishment of the Distinction of Sex . 20 
2. Diagram of the Primitive Urogenital Organs in the Embryo 
previous to Sexual Distinction 21 
3. The Testis in situ 22 
4. The Testicle, and the Elements of the Spermatic Cord . 23 
5. Vertical Section of the Testicle, to show the Arrange- 
ment of the Ducts 28 
6. Diagram Exhibiting the Cycle of Phases of Spermatogenesis 
(Rat) 33 
7. Diagram Showing the Reduction of the Chromosomes 
during Spermatogenesis 35 
8. Base of the Bladder, with the Vas Deferentia and Vesiculae 
Seminales 38 
9. Showing the Structure of the Floor of the Prostatic 
Urethra 39 
to. The Seminal Vesicles and Ducts 40 
11. Posterior View of the Uterus and Appendages ... 41 
12. Section of the Ovary of the Cat (10 diameters) ... 48 
13. The Cavity of the Uterus and Adjacent Structures . . 51 
14. The Utero-ovarian Vascular Circulation 53 
15. Section of the Female Pelvis, showing Position of Viscera 55 
16. Human Spermatozoa on the Flat and in Profile ... 80 
17. Human Spermatozoa on the Flat and in Profile . . .81 
18. The Nucleus of a Human Spermatozoon .... 83 
19. Human Spermatozoa 84 
20. Human Spermatozoon . 85 
11 12 
ILLUSTRATIONS. 
FIG. PAGE 
21. Human Spermatozoon 85 
22. Microscopic Field of Human Spermatozoa .... 87 
23. The Sex-membrane of the Human Spermatozoon . . 89 
24. Human Spermatozoon 90 
25. Microscopic Field of Human Spermatozoa .... 92 
26. Human Spermatozoa 93 
27. A Microscopic Field of Human Spermatozoa ... 94 
28. A Field of Dead Female-producing Spermatozoa . . 95 
29. An Interesting Field of Human Spermatozoa ... 96 
30. Human Spermatozoa Deformed 99 
31. A Spermatozoon of a Cock 101 
32. Spermatozoa of a Cock less the Nucleus .... 103 
33. A Field of Spermatozoa from the Cock 104 
34. Figures showing Various Stages in the Development of the 
Graafian Follicle of the Rabbit 107 
35. The Human Ovum; Highly Magnified . . . .111 
36. Diagram showing the Reduction of the Chromosomes 
during the Maturation of the Ovum . . . . .120 
37. Diagram showing the Similarity of the Maturation Phe- 
nomena to those of Spermatogenesis 121 
38. The Production of a Male Rat Zygote, as Witnessed by 
Sabotta 150 
39. The Production of a Female Bat Zygote, as Witnessed by 
Van der Strict (from Schafer) 151 
40. Spermatozoa of Bat 153 
41. Spermatozoa of Raja 153 
42. Spermatozoa of Fish 155 
43. Spermatozoa of Bullfinch 156 
44. Spermatozoa of Insect (Calathus) 157 
45. Illustrating the Production of Male and Female, in the 
Heterakis 162 The 
Key to Sex Control 
CHAPTER I. 
HISTORY OF SEX DETERMINATION. 
The problem of sex determination is probably a very 
old one. In fact, there are many rules and regulations 
in the laws of early civilizations, especially in the Mosaic 
laws of the Hebrews, which would lead us to belie, c that 
this important question was considered in those early 
times. It is reasonable to suppose that, in ancient 
times, when the security and welfare of the people de- 
pended almost altogether on the soldiery, the problem 
of sex-control received serious consideration by the wise 
men of the court, and that the laws laid down by them 
were of such a nature as to give the greatest chances of 
male-production. Not only were soldiers wanted, but 
male heirs to the throne were necessary, a thing very 
close to the heart of the monarch. 
It is only in modern times, however, that any serious 
steps have been taken toward the solution of the problem 
of sex-control; and only since the renowned discovery 
of the cell by Schleiden and Schwann, in 1838-39, that 
any real scientific work has been done in this direction. 
13 14 
THE CELLULAR DETERMINATION OF SEX. 
In fact, up to the present time, the work done on this 
problem is totally unworthy of its vast importance and 
far-reaching possibilities. 
Investigators in this line of research may be divided 
into two groups: those who believe that external con- 
ditions determine the sex and those who maintain that 
the sexual cells differ from the first. Of these, workers 
in the first group were the earlier and, until recently, 
predominant; but, at present, scientists generally recog- 
nize the theory that sex determination depends primarily 
upon the sexual cells and not upon external conditions 
affecting the embryo. It will be seen that many con- 
flicting theories have been advanced, some fanciful, some 
ingenious, but that no generally accepted laws have been 
laid down. 
Among the early investigators was Charles Darwin, 
who reviewed the evidence obtainable in his time and 
expressed the belief that the tendency to produce male 
or female offspring was inherited and that by a process 
of natural selection it was adjusted to the needs of the 
species, but he did not discuss the nature of the deter- 
mining factors. G. Canestrini was of the opinion that 
sex is determined by the number of spermatozoa that 
enter the ovum, but we now know that only one sper- 
matozoon normally conjugates with an ovum. Pro- 
fessor Thury and C. Diising expressed opinions that ova 
fertilized soon after ovulation give rise to females, while 
those impregnated later produce males. Convincing 
evidence exists as to the effect of delay in fertilization. 
J. D. Hofacker, in 1823, and M. O. Sadler, in 1830, col- 
lected a large series of statistics from which they drew 
the conclusion that, when the male parent is older and HISTORY OF SEX DETERMINATION. 
15 
more mature, more males are produced. Some investi- 
gators have claimed that the sex of the offspring tends 
to be that of the less vigorous parent; while others have 
urged that the most vigorous parent gives his or her sex 
to the progeny. A large number of careful investigators 
have been led to believe that conditions of nutrition play 
a large part in determining sex, but in nearly every case 
other observers have obtained conflicting results or have 
drawn different deductions from the facts. E. Yung, 
from a number of interesting experiments, found that 
when tadpoles were reared under normal conditions, the 
proportion of male to female was about 43 : 57; but 
that when a flesh diet was provided, the percentage of 
females was greatly increased. Mrs. Treat showed that 
starved caterpillars turned into males, and E. Maupas 
took certain rotifers and demonstrated a relation be- 
tweeen abundant nutrition and an excessive production 
of females. P. Gedds and J. A. Thompson (1889) 
asserted that factors external to sexual cells had a pre- 
dominating importance in the determination of sex. 
They conceived of sex as an effect of an alternating 
rhythm of anabolism and katabolism to be observed 
throughout the living world, and supposed that female- 
ness was an expression of the anabolic or constructive 
processes of living matter, whilst maleness represented 
the katabolic, destructive, or liberating processes. Pro- 
fessor Thompson, in a later work (1907), however, prac- 
tically withdrew his theory. Dawson, in his work on 
sex determination, has suggested that the ova from the 
right ovary produce male and those from the left, female, 
and reported many cases of male-production from the 
right ovary and some female from the left. This theory, 16 
THE CELLULAR DETERMINATION OF SEX. 
however, is disproved by the fact that there are cases 
on record where women, after having one ovary removed, 
have produced both sexes. The author personally 
knows of a case in which a woman had one ovary re- 
moved and subsequently gave birth to a girl and two 
years later produced a fine boy. It is probable that the 
arteries to the right ovary are just a little larger than 
those to the left, and, in that event, a Graafian follicle 
would reach maturity sooner in it than in the left and 
this would increase the chance for male-production from 
early insemination after menstruation. It is also a fact 
that women lie on the right side more than on the left 
and, when a Graafian follicle matures in the right ovary, 
the ovum is assisted to the fimbriated extremity of the 
Fallopian tube by gravity, where it is delivered to the 
spermatozoon before it has become female-producing. 
When the Graafian follicle is matured in the left ovary 
and the woman lies on the right side after insemination, 
external migration of the ovum is almost sure to follow 
and, in that event, more time is consumed by the ovum 
in reaching the fimbriated end of the oviduct and the 
spermatozoon has had more time to become female- 
producing. 
Investigators in the second group-those who believe 
that sex is predetermined in the sexual cells-have been 
less numerous than those in the first group, but they 
occupy more tenable ground. In fact, all true progress 
toward the discovery of the factors which determine sex 
became possible only after the enunciation of the cell- 
theory by Schleiden and Schwann. A long list of sub- 
sequent investigators have placed the cell-theory upon a 
firm basis and have done much to elucidate the mysteries HISTORY OF SEX DETERMINATION. 
17 
of heritage and sex. Among the most important may 
be mentioned Kolliker, who, in 1841, demonstrated that 
the spermatozoa are not parasites but are cells generated 
in the testes; and Schweigger, Seidel, and La Valette St. 
George who, in 1865, proved that the spermatozoon con- 
tains not only a nucleus, as Kolliker believed, but also 
cytoplasm. Not less important was the discovery of 
Oscar Hertwig that fertilization of the ovum is accom- 
plished by its union with one spermatozoon, and only 
one. In 1855, Virchow established the universality of 
cell-division, expressed in his since famous aphorism, 
" omnis cellula e cellula." These and other discoveries 
demonstrated that the cell is the basis of life and led 
Wilson to remark that " a single cell may contain within 
its microscopic compass the sum total of the heritage of 
the species." Among workers in the field of sex deter- 
mination under the second group, the names of Grego,n 
Mendel and E. B. Wilson stand out preeminent. Gregon 
Mendel was born in 1822, from peasant parentage, and 
later became a monk and abbot of Briinn. In 1865, he 
published an account of his experiments, but these valu- 
able writings were not appreciated until recently and 
now bid fair to give him a name in the biological world 
second only to that of Darwin. From numerous ex- 
periments carried on through a long period of years, he 
discovered and elaborated many of the physiological 
processes of heredity upon which later biologists have 
largely depended. A brief description of what is now 
called Mendelism is not possible, for the reason that his 
experiments were extensive and many of his deductions 
involved; but while many of his theories are more in- 
genious than conclusive, his work is generally recognized 18 
THE CELLULAR DETERMINATION OF SEX. 
as having been of a very high order. E. B. Wilson 
(1909) published a work which has a very important 
bearing on sex determination. In it he gives a full dis- 
cussion of the accumulated facts concerning the existence 
of different kinds of sexual cells and the nuclear changes 
which occur in ovogenesis and spermatogenesis. He con- 
siders over a hundred different species of insects, myria- 
pods, and arachnids in which two kinds of spermatozoa 
are produced. These spermatozoa are formed in pairs, 
and the mother cell which gives rise to each pair exhibits 
paired chromosomes, one member of each pair passing 
into each spermatozoon. The mother cell contains also 
an impaired element, consisting in its simplest form of 
a single large chromosome, which Wilson terms the 
" X " element. This " X " element passes into one or 
the other of the spermatozoa, from which it results that 
spermatozoa of two kinds are formed in equal numbers, 
the difference being the presence or absence of the " X " 
element. Eggs fertilized by spermatozoa containing the 
" X " element become females; those without it, males. 
Thus the " X " element becomes the index of sex. 
The author, in the present volume, claims that neither 
the fertilizing cell nor the egg cell has any sex tendency, 
per se, but that sex is determined solely by the manner 
and completeness of entrance of the spermatozoon into 
the ovum. If the sperm cell enters entirely into the 
cytoplasm of the egg, a male is produced; if the entire 
cell does not enter the egg, a female is produced; and 
if two or more cells enter the ovum, an abnormality is 
produced. CHAPTER II. 
THE MALE ORGANS OF GENERATION. 
The human male generative organs consist of two 
testicles, vesiculae seminales, penis, and the prostate gland 
which is generally included among these organs. The 
testicles generate and develop the spermatozoa which 
are transmitted from the seminiferous tubules to the 
vesiculae seminales by the vas deferens. The vesiculae 
seminales receive and retain the semen until it is ejected 
by orgasm. The penis is an erectile organ through which 
the semen as well as the urine is discharged. The func- 
tion of the prostate gland is not clearly understood. 
Development of the Generative Organs.-The first 
rudiments of the organs of reproduction are essentially 
the same in the two sexes; they consist of the genital 
ridge (Fig. i), situated on the mesial side of each Wolffian 
body, and from it are developed the testicles in one sex, 
and the ovaries in the other. As the embryo grows, the 
ridge gradually becomes pinched off from the Wolffian 
body, with which it is at first continuous, though it still 
remains connected to the remnant of this body by a fold 
of peritoneum, the mesorchium. About the seventh 
week the distinction of sex begins to be perceptible, in 
that the epithelium on the genital ridge, called " germ- 
epithelium," though in general it has a tendency to 
become columnar, has its cells, on the whole, flatter and 
smaller in the male than in the female. 
19 20 
THE CELLULAR DETERMINATION OF SEX. 
Development of the Male Organs.-The tubuli 
seminiferi of the testicle appear at an early period. It 
is believed that they are formed by the extension of 
epithelial cells from the surface of the genital ridge into 
its blastema; rows of cells are thus developed which 
become the lining cells of the seminal ducts. In some 
animals (e.g., reptiles) the segmental tubes of the 
Wolffian body (Fig. 2, w) have been found to extend 
Fig. 1.-Enlarged View from the Front of the Left Wolffian Body Before 
the Establishment of the Distinction of Sex. (From Farre, after Kobelt.) 
a, a, b, d, Tubular structure of the Wolffian body; e, Wolffian duct; f, its upper 
extremity; g, its termination in x, the urogenital sinus; h, the duct of Muller; i, 
its upper, still closed, extremity; k, its lower end, terminating in the urogenital 
sinus; I, the mass of blastema for the reproductive organ, ovary or testicle. 
into the body of the testis and to form the tubes of this 
organ, which becomes lined with cells derived from the 
germ-epithelium; and it is probable that a similar pro- 
cess takes place in birds and mammals. 
In the male sex, the Mullerian ducts (Fig. 2, m m) 
disappear with the exception of their lower ends. These 
unite in the middle line, and open by a common orifice 
into the urogenital sinus (Fig. 2, ug). This constitutes 
the utriculus hominis or sinus prostaticus. Occasionally, 
however, the upper end of the duct of Muller remains 
visible in the male, constituting the little pedunculated 
body called the hydatid of Morgagni, sometimes found THE MALE ORGANS OF GENERATION. 
21 
in the neighborhood of the epididymis, between the 
testes and globus major. 
The head of the epididymis, its canal, the vas deferens, 
and the ejaculatory duct are formed from the canals and 
Fig. 2.-Diagram of the Primitive Urogenital Organs in the Embryo 
Previous to Sexual Distinction. 
The parts are shown chiefly in profile, but the Mullerian and Wolffian ducts are 
seen from the front. 3, Ureter; 4, urinary bladder; 5, urachus; ot, the mass of 
blastema from which ovary or testicle is afterward formed; W, right Wolffian body; 
x, part at the upper apex from which the coni vasculosi are afterward developed; 
w, w, right and left Wolffian ducts; m, m, right and left Mullerian ducts uniting 
together and with the Wolffian ducts in gc, the genital cord; ug, sinus urogenitalis; 
i, lower part of the intestine; cl, common opening of the intestine and urogenital 
sinus: cp, elevation which becomes clitoris or penis; Is, ridge from which the labia 
majora or scrotum is formed. 
duct of the Wolffian body (Fig. 2, w). One or more of 
the tubes of the Wolffian body form the vas aberrans 
and a structure described by Giraldes, and called after 
him " the organ of Giraldes," which bears a good deal 22 
THE CELLULAR DETERMINATION OF SEX. 
of resemblance to the organ of Rosenmuller in the other 
sex. It consists of a number of convoluted tubules 
lying in the cellular tissue in front of the cord and close 
to the head of the epididymis. 
Descent of the Testes.-At 
an early period of foetal life the 
testes are placed at the back 
part of the abdominal cavity, in 
front and below the kidneys, 
behind the peritoneum. At 
about the third month of foetal 
life, the gubernaculum testis 
(Fig. i, Z) makes its appearance. 
This structure is a slender band 
which extends from the internal 
ring to the epididymis and body 
of the testicle, and passes up- 
ward in front of the kidney 
toward the diaphragm. As de- 
velopment advances the testicle 
is so covered by the peritoneum 
as to form a mesentery, the 
mesorchium, which also encloses 
the gubernaculum and has two 
folds, one above and one below 
the testicle. The one above the 
testicle ultimately contains the spermatic vessels; the one 
below contains the lower part of the gubernaculum, which 
has developed into a thick cord; it ends below at the 
internal ring in the processus vaginalis, which is now in 
the inguinal canal. The lower end of the gubernaculum 
becomes a thick cord by the fifth month, while the upper 
Fig. 3--The Testis in situ; 
the Tunica Vaginalis Having 
been Laid Open. 
a, Artery of cord; c, cre- 
master; d, tunica vaginalis pari- 
etal layer; t, testis; h, head; b, 
body; I, tail. THE MALE ORGANS OF GENERATION. 
23 
part has disappeared. The gubernaculum extends to the 
inguinal canal at about the sixth month, and later to the 
bottom of the scrotum. The processus vaginalis projects 
Fig. 4.-The Testicle, and the Elements of the Spermatic Cord. 
A, The vas deferens; B, spermatic artery; C, spermatic veins. (Campbell.) 
itself downward into the inguinal canal, where it gradu- 
ally forms a cul-de-sac, which ultimately reaches the bot- 24 
THE CELLULAR DETERMINATION OF SEX. 
tom of the scrotum. The cul-de-sac is invaginated by the 
testicle, and, as the body grows, the gubernaculum does 
not grow commensurately with the growth of the other 
parts. The testicle, being attached to the bottom of 
the scrotum by the gubernaculum, is prevented from 
rising with the body as it grows, and thus is drawn into 
the inguinal canal and ultimately into the scrotum. At 
the eighth month the testicle has reached the scrotum. 
The processus vaginalis for a short period communicates 
at its upper extremity with the peritoneal cavity. The 
upper part of the pouch becomes closed at about the 
time of birth, and this obliteration extends downward 
to within a short distance of the testicle. The process 
of peritoneum surrounding the testis, which is now cut 
off from the general peritoneal cavity, constitutes the 
tunica vaginalis. A small cord in the female, corre- 
sponding to the gubernaculum in the male, descends to 
the inguinal region, and later forms the round ligament 
of the uterus. A process of peritoneum accompanies it 
along the inguinal canal, analogous to the processus 
vaginalis in the male; it is called the canal of Nuck. 
The testes are suspended in their tunics (Figs. 3, 4) 
by the spermatic cord. Each gland is of an oval form, 
compressed laterally, and has an oblique position in the 
scrotum. The anterior border and lateral surfaces, as 
well as both extremities of the organ, are convex, free, 
smooth, and invested by the tunica vaginalis. The 
posterior border, to which the cord is attached, receives 
only a partial investment from the membrane. Lying 
along this posterior border is a long, narrow, flattened 
body, named the epididymis, from its relation to the 
testis (Fig. 3). It consists of a central portion, or body; THE MALE ORGANS OF GENERATION. 
25 
an upper enlarged extremity, the globus major, or head; 
and a lower pointed extremity, the tail, or globus minor. 
The globus major is intimately connected with the 
upper end of the testicle by means of its efferent ducts, 
and the globus minor is connected with its lower end by 
cellular tissue and a reflection of the tunica vaginalis. 
The outer surface and upper and lower ends of the 
epididymis are free and covered by serous membrane; 
the body is also completely invested by it, excepting 
along its posterior border. The epididymis is connected 
to the back of the testis by a fold of serous membrane. 
Attached to the upper end of the testis or to the epididy- 
mis are one or more pedunculated bodies. One of them 
is pretty constantly found between the globus major 
of the epididymis and the testicle, and is believed to be 
the remains of the upper extremity of the Mullerian 
duct (Fig. 2, mm). It is termed the hydatid of Mor- 
gagni. The average dimensions of each testis are 
from one and a half to two inches in length, one 
inch in breadth, and an inch and a quarter in the 
antero-posterior diameter, and the weight varies from 
six to eight drachms, the left testicle being a little 
larger. 
At an early period of foetal life the testes are contained 
in the abdominal cavity, behind the peritoneum. Before 
birth they descend to the inguinal canal, along which 
they pass with the spermatic cord, and, emerging at the 
external abdominal ring, they descend into the scrotum, 
becoming invested in their course by numerous cover- 
ings derived from the serous, muscular, and fibrous 
layers of the abdominal parietes, as well as by the 
scrotum. The coverings of the testes are: the 26 
THE CELLULAR DETERMINATION OF SEX. 
Skin; 
Dartos, scrotum; 
Intercolumnar, or external spermatic fascia; 
Cremasteric fascia; 
Infundibuliform, or fascia propria (internal spermatic 
fascia); 
Tunica vaginalis; 
all of which support and protect the testes. The scrotum 
is a cutaneous pouch which contains the testes and a 
part of the spermatic cords. The median line, or raphe, 
divides it laterally into halves. Its external aspect 
varies under different circumstances; thus, under the 
influence of warmth and in old and debilitated persons 
it becomes elongated and flaccid, but under the influ- 
ence of cold and in the young and robust it is short, 
corrugated, and closely applied to the testes. 
The scrotum consists of two layers, the integument 
and the dartos. 
The integument is very thin, brownish in color, and 
thrown into folds or rugae in its normal condition. It 
is beset with thinly scattered short hairs, the roots of 
which may be seen through the skin, and is provided 
with sebaceous glands, the secretion of which has a 
peculiar odor. 
The dartos is a thin layer of loose, very vascular tissue 
endowed with contractility from the smooth muscular 
fibres it contains. It forms the proper tunic of the 
scrotum, and is continuous, around the base of the 
scrotum, with the two layers of the superficial fascia of 
the groin and perineum, and sends inward a distinct 
septum, septum scroti, which divides it into two cavities 
for the two testes, the septum extending between the THE MALE ORGANS OF GENERATION. 
27 
raphe and the under surface of the penis as far as its 
root. The dartos is closely united to the skin externally, 
but connected with the subjacent parts by delicate 
areolar tissue, upon which it glides with the greatest 
facility. 
The intercolumnar fascia is a thin membrane which 
is prolonged downward around the surface of the cord 
and testis. It is separated from the dartos by loose 
areolar tissue, which allows considerable movement of 
the latter upon it, but it is intimately connected with the 
succeeding layers. 
The cremasteric fascia consists of scattered bundles 
of muscular fibres, which are continuous with the lower 
border of the internal oblique muscle of the abdomen. 
The fascia propria is a thin membranous layer which 
loosely invests the surface of the cord. It is acquired 
during the descent of the testis in the foetus. 
It is very evident from the anatomy of the tunics of 
the testes, as shown in the abundance of loose areolar 
tissue, that nature has provided well against their com- 
pression. This protection is so perfect that it is difficult 
to grasp and hold the normal testicle between two 
fingers. Thus in the free and easy gliding movement of 
the testes within the tunics the male is protected 
against their compression and the consequent pain and 
the premature dislodgment (before maturity) of the 
spermatozoa from the mother cells. The testicle of a 
blacksmith while shoeing horses is subject to more or 
less compression, which produces the premature rupture 
of the spermatozoa from the mother cells, and this 
probably explains the high mortality in their male 
children (see pages 67, 68, 69). 28 
THE CELLULAR DETERMINATION OF SEX. 
Structure of the Testis.-The testis is enclosed in a 
strong capsule (Fig. 5, c), the tunica albuginea. This is 
a dense, unyielding, fibrous membrane, of white color and 
of considerable thickness, which immediately invests the 
soft substance of the 
testis and preserves 
the form of the 
gland. It is com- 
posed of bundles of 
fibrous tissue which 
interlace in every 
direction. The outer 
surface is covered 
by the tunica vagi- 
nalis, except along 
the posterior border 
of the testis, where 
the spermatic ves- 
sels pass through 
and the two extrem- 
ities of the epididy- 
mis are attached. 
In the interior 
(Fig. 5, b), the 
fibrous tissue of the 
tunica albuginea is 
prolonged from the 
posterior border for a short distance into the substance of 
the gland, so as to form within it an incomplete vertical 
septum, known as the corpus Highmori and named by 
Astley Cooper mediastinum testis. It extends from the 
upper nearly to the lower end of the gland, and it is wider 
Fig. 5.-Vertical Section of the Testicle, 
to Show the Arrangement of the Ducts. 
a, Lobule; c, tunica albuginea; b, its septa; d, 
globus major; e, body of epididymis; /, globus minor; 
g, vas aberrans; h, spermatic artery; i, vasa effer- 
entia; j, rete testis; k, vasdeferens; I, mediastinum. THE MALE ORGANS OF GENERATION. 
29 
above than below. The firm tissue of which it is com- 
posed is traversed by a network of seminal ducts (Fig. 
5, a), and by the larger blood-vessels of the gland, which 
are lodged in channels formed in the fibrous tissue. 
From the front and side of the corpus Highmori 
numerous slender fibrous cords and imperfect septa of 
connective tissue are given off in radiating directions, 
and are attached by their outer ends to the internal 
surface of the tunica albuginea at different points, thus 
incompletely dividing the glandular substance into 
lobules. According to Kblliker, smooth muscular fibres 
are prolonged upon these septula. The whole internal 
surface of the tunica albuginea is covered by a multitude 
of fine blood-vessels, which are branches of the spermatic 
artery and veins, and are held together by a delicate 
areolar web. Similar delicate ramifications of vessels 
are seen on the various fibrous offshoots of the mediasti- 
num, upon which the blood-vessels are thus supported 
in the interior of the gland. 
The Seminiferous Tubules.-The glandular substance 
of the testis which is included in the fibrous framework 
formed by the albuginea (Fig. 5, a), the mediastinum, 
and the trabeculae, is a mass of convoluted tubules known 
as the tubuli seminiferi, which are somewhat loosely 
bound together by areolar tissue into the lobes or lobules 
above mentioned. Of these lobes there are some one 
hundred to two hundred (Krause) or more; they are 
of unequal size, the middle ones being the larger, and 
are imperfectly separated from one another, the septa 
being incomplete. In each lobe are two, three, or more 
seminiferous tubules closely convoluted, and here and 
there branched, especially at their anterior or distal 30 
THE CELLULAR DETERMINATION OF SEX. 
extremity, where, in a cortical zone near the albuginea, 
they are stated to communicate frequently laterally 
with one another. "It is not difficult to unravel the 
tubules for some distance, for their walls are moderately 
strong, and their diameter (0.2 mm.) large compared 
with those of other tubular glands, such as the kidney " 
(Quain). The thickness of the walls just referred to 
is necessary to prevent the escape of the spermatozoa 
from the tubes. The movement of the spermatozoon 
is comparatively slow and weak while it is in the 
seminiferous tubule, but becomes more rapid and pow- 
erful as it approaches the vesicular seminales, which 
are reached by its inherent power. On section of a 
seminiferous tubule, many spermatozoa are seen, but 
only those fully matured are able to move. 
The length of the seminiferous tubules has been 
variously estimated by different authors. Lauth has 
estimated their length to be on an average rather greater 
than two feet, and their number between eight hundred 
and nine hundred, while Munro has estimated their total 
number to be three hundred, and the length of each is 
about sixteen feet. The diameter varies from to tItt 
of an inch. The tubuli are pale in color in early life, 
but in old age they acquire a deep yellow tinge. They 
have a smooth contour, but this is interrupted at intervals 
by small dilatations, which are more numerous near the 
commencement of a tubule than near its termination. 
The walls of the seminiferous tubules are composed of 
several layers of flattened cells. Of these only the inner- 
most layer is complete, being formed of epithelioid cells 
closely united edge to edge into a basement membrane. 
This is strengthened by the other layers, which, however, THE MALE ORGANS OF GENERATION. 
31 
exhibit intervals between the flattened cells which com- 
pose them, these intervals becoming very marked in the 
outermost layers. In consequence of their being thus 
formed of several layers, the walls of the tubules have a 
concentrically striated appearance in cross-section. The 
tubules are occupied by an epithelium which consists of 
several irregular layers of cells, among which the seminal 
filaments or spermatozoa may be observed in different 
stages of development (Fig. 6). In different tubules of 
the same testis and even in parts of the same tubule the 
state of development of the spermatozoa may be various, 
and the epithelium presents corresponding differences, 
both in the number of its layers and in the state of the 
cells. 
Structure of the Seminiferous Tubules.-The semi- 
niferous tubules are formed of a thick basement-mem- 
brane, and contains several layers of epithelial cells. 
Of these layers, the first, which is composed of the outer 
layer or lining cells (spermatogonia), forms the outer- 
most zone. They are clear cubical or somewhat flattened 
cells, disposed in a single regular layer upon the basement 
membrane of the tubule (Fig. 6, z'). In some tubules 
one of these cells may here and there be seen to be 
elongated and to project between the cells of the next 
zone, where it comes into connection with a group of 
developing spermatozoa. Indications of cell division 
are also met with in this layer (Fig. 6, y). The enlarged 
cells of this layer are the cells of Sertoli (Fig. 6, z', z"). 
Next to this lining epithelium is a zone of larger cells, 
spermatocytes (Fig. 6, y). The nuclei of these cells are 
usually in some stage of hetero- or homo-typical mitotic 
division; these cells may be two or three deep (Fig. 6, z). 32 
THE CELLULAR DETERMINATION OF SEX. 
Next to these, and most internal, are to be seen in 
some tubules (Fig. 6, y and x) a large number of small 
protoplasmatic cells with simple spherical nuclei (sper- 
matid, Fig. 6, x). In other tubules, the spermatids are 
elongated, and the nucleus is at one end, and in others 
again these elongated cells are converted into evident 
spermatozoa, which lie in groups of four to eight, or 
sixteen, " and sometimes as many as twenty are attached 
to a mother cell " (Kolliker). Their heads are attached 
to one of the deeper cells of the lining epithelium (Sertoli 
cells), and their tails project into the lumen of the tubule. 
As they mature the mother cell becomes elongated, 
which causes them gradually to shift altogether toward 
the lumen; when the attachment to the mother cell is 
severed, they become free. During the time that this 
crop of spermatozoa has been forming, another set of 
spermatocytes has been produced by the division of the 
spermatogonia, and on discharge of the spermatozoa 
the process is repeated. 
Spermatogenesis.-According to Schafer, who is 
quoted by Quain, the spermatozoa are developed from 
the small cells (spermatids) which form the innermost 
stratum of the seminal epithelium, and these are them- 
selves produced by the division of the large spermato- 
cytes of the second layer. It is probable that fresh 
spermatocytes are formed by division of the lining 
epithelium-cells or spermogons. The cycle of changes, 
therefore, which takes place is as follows: I. Division 
of a lining epithelium-cell or spermogon into two, one 
of which grows larger (growing cells of H. H. Brown), 
becomes a spermatocyte, and passes into the second 
layer, while the other remains in the first layer; 2. Di- THE MALE ORGANS OF GENERATION 
33 
Fig. 6.-Diagram Exhibiting the Cycle of Phases of Spermatogenesis 
(Rat). 
s, Lining epithelium-cells are spermatogonia, seen dividing in 6; z', z", Sertoli 
cell; y, spermatocytes, with skein-like nuclear filaments. These cells are seen 
actively dividing in 5. x, Spermatids, forming an irregular column or clump in 
6, 7, 8, and 1, and connected to an enlarged Sertoli cell, a', of the lining epithelium 
in 2, 3, 4, and 5. In 6, 7, and 8 advanced spermatozoa of one crop are seen between 
columns of spermatids of the next crop. 34 
THE CELLULAR DETERMINATION OF SEX. 
vision of the spermatocyte; 3. Further division of the 
daughter-spermatocytes thus produced. The four cells 
(spermatids) which result from this double division pos- 
sess only one-half the somatic number of chromosomes 
in their nuclei, " reduction " having been effected in the 
final cell-division by which the spermatids are produced 
(Fig. 7). Elongation of the spermatids and their gradual 
conversion into spermatozoa follow. As they undergo 
this conversion their grouping becomes more evident, 
and each group is found to be connected with a cell of 
Sertoli (Fig. 6, z'), which undoubtedly ministers to their 
nutrition. 
The tubules are enclosed in a delicate plexus of 
capillary vessels and are held together by an intertubular 
connective tissue which presents large interstitial spaces 
lined by endothelium, and these are supposed to be the 
beginning of the lymphatic vessels of the testis. In the 
free spaces of the lobules the tubuli become less con- 
voluted, assume a nearly straight course, and unite 
together to form from twenty to thirty larger ducts, 
about Aq of an inch in diameter, and these, from their 
straight course, are called tubuli recti. 
The tubuli recti enter the fibrous tissue of the mediasti- 
num and pass upward and backward, forming, in their 
ascent, a close network of anastomosing tubes, which 
are merely channels in the fibrous stroma, as they have 
no proper walls; this network constitutes the rete testis 
(Fig. 5, j). At the upper end of the mediastinum the 
vessels of the rete testis terminate in from twelve to 
twenty ducts, the vasa efferentia (Fig. 5, i), which per- 
forate the tunica albuginea and carry the seminal fluid 
from the testis to the epididymis (Fig. 5, e). Their THE MALE ORGANS OF GENERATION. 
35 
course is at first straight; they then become enlarged 
and exceedingly convoluted, and form a series of conical 
masses, the coni vasculosi, which together constitute the 
globus major of the epididymis. Each cone consists of 
a single convoluted duct from six to eight inches in 
Fig. 7.-Diagram Showing the Reduction of the Chromosomes during 
Spermatogenesis. 
5, Spermatocyte of the first order; d.s, the daughter spermatocytes; sp, spermatids. 
length, the diameter of which gradually decreases from 
the testis to the epididymis. Opposite the base of the 
cones the efferent vessels open at narrow intervals into 
a single duct, which constitutes, by its complex convolu- 
tions, the body and globus minor of the epididymis. 
When the convolutions of this tube are unravelled, it 
measures upward of twenty feet in length, and increases 
in breadth and thickness as it approaches the vas 36 
THE CELLULAR DETERMINATION OF SEX 
deferens. The convolutions are held together by fine 
areolar tissue and by bands of fibrous tissue. 
The vasa recta are of smaller diameter than the 
seminal tubes, and have very thin parietes. They, as 
well as the channels of the rete testis, are lined by a 
single layer of flattened epithelium. The vasa efferentia 
and the tubes of the epididymis have walls of consider- 
able thickness, on account of the presence in them of 
muscular tissue, which is arranged principally in a circu- 
lar manner. These tubes are lined by columnar ciliated 
epithelium, which is motionless in the human species. 
The vas deferens is the continuation of the epididymis 
(Fig. 5, k). Commencing at the lower part of the globus 
minor (Fig. 3, Z), it ascends along the posterior border 
of the testis and the inner side of the epididymis, and 
along the back part of the spermatic cord, through the 
spermatic canal to the internal or deep abdominal ring. 
From the ring it curves around the outer side of the 
epigastric artery, crosses the external iliac vessel, and 
descends into the pelvis at the side of the bladder; it 
arches backward and downward to its base, crossing over 
the obliterated hypogastric artery and to the inner side 
of the ureter (Fig. 8, d). At the base of the bladder it 
lies between that viscus and the rectum, running along 
the inner border of the vesiculae seminales. In this 
situation it becomes enlarged and sacculated, forming the 
ampulla (Fig. 8), and then, narrowing at the base of the 
prostate, unites with the duct of the vesicula seminalis 
to form the ejaculatory duct (Fig. 9). The vas deferens 
has dense walls, is about two feet long, cylindrical in 
form, about a line and a quarter in diameter, and its 
lumen is extremely small, measuring about one-half a THE MALE ORGANS OF GENERATION. 
37 
line. Its structure shows three coats: I. An external 
or cellular coat; 2. A muscular coat, consisting of two 
layers of smooth muscular fibre; an outer, longitudinal, 
and an inner, circular. 3. An internal or mucous coat, 
which is pale, and arranged in longitudinal folds. 
Vesiculae Seminales.-The seminal vesicles (Figs. 8 
and 9) are two convoluted membranous pouches sit- 
Fig. 8.-Base of the Bladder, with the Vasa Deferentia and Vesiculte 
Seminales. 
a, Ampulla; b, ureter; e, vesiculae seminales; d, vas deferens; c, prostate gland. 
uated between the base of the bladder and the rectum; 
they serve as reservoirs for the semen and secrete a 
fluid to be added to the secretion of the testicles. When 
distended, they form two long sacculated bodies, some- 
what flattened on the side, the broad end being directed 
backward and the narrow end forward toward the 38 
THE CELLULAR DETERMINATION OF SEX. 
prostate, next the bladder, to which they are firmly 
attached. Each sac is somewhat pyramidal in form. 
They measure about two and one-half inches in length, 
about five lines in width, and two or three lines in 
thickness. They vary, however, in size, not only in 
different individuals, but also in the same individual on 
the two sides. Their upper surface is in contact with 
the base of the bladder, and extends from near the 
termination of the ureters to the base of the prostate 
gland. Their surface rests upon the rectum, from which 
they are separated by the recto-vesical fascia. Their 
posterior extremities diverge from each other upon the 
walls of the bladder. Their anterior extremities are 
pointed and converge toward the base of the prostate 
gland, where they join to form the ejaculatory duct 
(Fig. 9). A considerable amount of smooth muscular 
tissue is found covering the posterior surface and extend- 
ing transversely between the two vesicles; there are 
also longitudinal fibres traceable over the vesicles from 
those of the bladder, and these serve as compressors, by 
the action of which their contents may be discharged. 
Each vesicula consists of a single tube (Fig. 8, e), 
coiled upon itself, and gives off several irregular blind 
diverticula; the separate coils, as well as the diverticula, 
being bound together by fibrous tissue. When uncoiled, 
this tube is about the diameter of a quill, and varies in 
length from four to six inches; it terminates posteriorly 
in a cul-de-sac. The ejaculatory ducts, two in number 
(Fig. 9), one on each side, are formed by the junction 
of the ducts of the vesiculae seminales with the vasa 
deferentia. Each duct is about three-quarters of an 
inch in length; it commences at the base of the prostate, THE MALE ORGANS OF GENERATION. 
39 
and runs forward and downward between the middle 
and lateral lobes, and along the side of the sinus pocularis, 
to terminate by a separate, slit-like orifice close to or 
Fig. 9.-Showing the Structures in the Floor of the Prostatic Urethra. 
A. Orifice of the ejaculatory ducts; B, verumontanum; C, the utricle; D, prostatic 
ducts; E, duct of Cowper's gland. (Campbell.) 
just within the margins of the sinus. The ducts diminish 
in size and converge toward their termination. 
Structure of the Vesiculae Seminales.-The vesiculae 
seminales are composed of three coats: an external or 40 
THE CELLULAR DETERMINATION OF SEX. 
fibro-cellular coat; a middle or muscular coat; and an 
internal or mucous coat. The ejaculatory ducts have 
essentially the same structure as the vesiculse seminales^ 
except that their coats are very much thinner. The 
mucous coat of the vesiculae seminales secretes and adds 
to the seminal fluid the whitish-colored mucus so char- 
acteristic of the semen. " The seminal vesicles are 
accessible to the rectal touch; hence by this route 
massage or milking of the ducts is performed " (Camp- 
bell). 
The Prostate Gland.-The prostate gland (Figs. 8, 9, 
and io) is situated at the neck of the bladder, and is 
pierced by the urethra and the ejaculatory ducts. It is 
somewhat chestnut-shaped and measures an inch and a 
Fig. io.-The Seminal Vesicles and Ducts. (Campbell.) 
half in breadth, an inch and a quarter in length, and half 
an inch in thickness. Its weight is about five drachms. 
Structure.-The prostate is made up of compound 
tubular glands embedded in an abundance of muscular 
fibres and connective tissue. The glands are lined by 
columnar epithelium, with smaller cells lying between 
them and the basement-membrane. The numerous THE MALE ORGANS OF GENERATION. 
41 
follicular glands are drained by elongated canals, which 
join to form from twelve to twenty small excretory 
ducts, which open into the floor of the prostatic portion 
of the urethra. 
The muscular tissue of the prostate forms the chief 
part of the stroma of the gland, and constitutes a con- 
tinuous layer inside the fibrous sheath, as well as a layer 
surrounding the urethra and blending with the sphincter 
of the bladder. 
Cowper's glands (Fig. 9) are two small, round lobulat- 
ed bodies of a yellow color, about the size of a pea. They 
are situated close above the bulb, and are enclosed by the 
transverse muscular fibres of the compressor urethrae. 
They have each a single excretory duct, are lined through- 
out with cylindrical epithelium, and secrete a mucoid 
fluid, which is ejaculated with the semen. It is probable 
that this secretion is produced only during sexual excite- 
ment, and excreted as above mentioned. 
The Penis.-The penis is the male organ of copulation. 
It consists of a root, body, and an extremity or the glans 
penis. The penis is composed of erectile tissue enclosed 
in three cylindrical fibrous compartments. The two 
corpora cavernosa are placed side by side along the upper 
part of the organ; the third, or corpus spongiosum, en- 
closes the urethra and is placed below. The urethra 
throughout its entire length is beset with mucous glands, 
the secretion of which is mixed with the ejaculated semen. CHAPTER HI. 
THE FEMALE GENERATIVE ORGANS. 
The human female generative organs consist of two 
ovaries, two Fallopian tubes, the uterus, and the vagina. 
The function of the ovaries is the maturation and the 
discharge of the ova. The Fallopian tubes, one of which 
is connected with each ovary, serve the purpose of 
selective fertilization of the ova while conducting them 
from the ovary to the uterus. The uterus receives and 
retains the fertilized ovum until the embryo becomes 
viable and fitted to maintain its existence independent 
of the placental connection with the mother. The vagina 
with its appendages receives the male organ in the act 
of copulation and subsequently discharges the foetus. 
The Ovaries.-The ovaries (Figs. 11, b, 15) are two in 
number and are analogous to the testes in the male. 
They are oval-shaped bodies, situated one on each side 
of the uterus, in the posterior layer of the broad ligament 
behind and below the Fallopian tubes. Each ovary is 
connected by its anterior straight margin with the broad 
ligament; by its lower extremity with the uterus by a 
proper ligament (Fig. 11, Z); and by its upper end with 
the fimbriated extremity of the Fallopian tube by the 
ovarian fimbria (Fig. 11, e). Its mesial and lateral sur- 
faces and posterior convex border are free. The ovaries 
are of a grayish-pink color, and present either a smooth 
or a puckered, uneven surface. They are each about 
42 THE FEMALE GENERATIVE ORGANS. 
43 
Fig. ii.-Posterior View of the Uterus and Appendages. 
a, Interior of vagina; b, the naked ovary: b', ovary in its bursa (formed by the broad ligament); c, Fallopian tube; 
d, fimbriae of the Fallopian tube and its opening; e, the fimbria connected with the outer end of the ovary; f, broad liga- 
ment; g, fundus; h, body; i, vaginal part; j, mouth; k, neck; I, ligament of the ovary; m, mesosalpinx; n, epoophoron. 44 
THE CELLULAR DETERMINATION OF SEX. 
an inch and a half in length, three-quarters of an inch in 
width, and about a third of an inch in thickness, and 
weigh from one to two drachms. The ovary possesses 
two extremities: (i) An outer, superior, or tubal ex- 
tremity. (2) An inner, inferior, or uterine extremity. 
The ovary has two surfaces, an inner surface, which is 
also upper; an outer surface, which is also lower. The 
posterior or free border is markedly convex. The 
anterior border is almost straight and is narrow. The 
anterior border is not free, but is joined to the posterior 
layer of the broad ligament by a peritoneal fold known 
as the mesovarium. There" is a groove in the anterior 
border called the hilum, through which vessels and 
nerves pass to the ovary and emerge from it. The 
posterior surface of the broad ligament covers the outer 
or lower surface of the ovary, while the mesosalpinx 
folds backward and inward over the inner or upper sur- 
face of the ovary (Fig. 11). The Fallopian tube passes 
around the posterior or free border and with the mesosal- 
pinx covers its entire medial surface. Thus we see the 
posterior surface of the broad ligament in contact with 
both surfaces of the ovary forming the ovarian bursa, 
which is held in position by gravity and the pressure of 
the small intestine against the mesosalpinx and Fallopian 
tube covering the medial face of the ovary (Fig. 11, b'). 
Situated between the broad ligament and the mesosal- 
pinx, according to Waldeyer, the ovary lies on the lateral 
pelvic wall and vertically when the woman takes the 
erect posture. Its tubal extremity is near the external 
iliac vein; its uterine end is directed downward. Its 
convex margin looks downward and backward toward 
the pelvic cavity and rectum, while its straight margin THE FEMALE GENERATIVE ORGANS. 
45 
or hilum lies laterally on the pelvic wall. Waldeyer 
also finds that it lies in a distinct but shallow groove 
limited above by the hypogastric artery and below by 
the uterus, in such a manner that the uterus lies along 
the convex margin of the ovary, and the hypogastric 
artery passes near the hilum or straight margin. In this 
connection it may be said that we can understand how 
gravitation may become a factor in sex production. If 
the woman knew which ovary had matured the ovum, a 
fact to be determined by pain or tenderness over the 
ovary during or immediately after mensturation, and 
should lie on that side after insemination, this position 
might hasten the ovum by gravitation to the fimbriated 
extremity (Fig. n, d) of the Fallopian tube, and thus 
augment very materially the production of a male by 
hastening the ovum to the spermatozoon in the Fallopian 
tube before the latter becomes aged, small, and female- 
producing. Some authors speak of the ovum as falling 
on its extrusion from the Graafian follicle, when in fact 
there is never a moment in the normal condition when 
there is a cavity at any point on the surfaces or borders 
of the ovary, or in the peritoneal sac, until the surgeon 
or anatomist opens the abdomen, at which moment the 
peritoneal cavity is produced. For the reason stated, 
some part of the peritoneum is constantly in close rela- 
tion with every part of the ovary. " Owing to the 
course pursued by the Fallopian tube round the ovary, 
the broad ligament forms a kind of curtain over the 
gland, and the ovary lies in a little pocket formed by the 
broad ligament, to which the name of bursa ovarii is 
applied " (Piersol) (Fig. n, b'). The time consumed 
in the passage of the ovum from the Graafian follicle 46 
THE CELLULAR DETERMINATION OF SEX. 
after its rupture to the Fallopian tube is absolutely 
problematical. 
When we understand the normal relation of the ovary 
and its situation in its bursa, we can very readily under- 
stand how in a certain number of cases there is a migra- 
tion of the ova, which pass across the abdominal cavity 
and come down the opposite tube; this is called external 
migration. In the case of bicornate uterus a corpus 
luteum may be found in the one ovary and pregnancy 
in the other side of the uterus. " Leopold and others 
have experimented by removing in an animal a tube and 
the opposite ovary. Later, if the animal became preg- 
nant the proof of external migration was positive. I 
have repeatedly demonstrated this external migration 
of the ovum by operation upon rabbits in the Loomis 
Laboratory. Older writers declared that there was inter- 
nal migration causing tubal pregnancy in the opposite 
tube, the ovum having passed through the uterus. This 
statement cannot be denied, neither can it be proved; 
hence we see that external migration does take place, 
whereas the occurrence of internal, though possible, has 
not been proven " (Edgar). 
The above experiments are proof positive that the 
woman, by lying on the side which matured the ovum, 
may hasten its progress to the fimbriated extremity of 
the Fallopian tube, where it is picked up and wafted to 
the uterus. If the woman is sure as to the ovary which 
matured the ovum and lies on that side for two to three 
hours after insemination the very best opportunity will 
have been given it to gravitate to and then be picked up 
by the fimbriated extremity of the tube. If the woman 
is not positive as to the ovary which matured the ovum, THE FEMALE GENERATIVE ORGANS. 
47 
she should choose the most comfortable side to lie on 
and remain on that side for four or five hours, just after 
insemination. If there is known to be a pathological 
condition in one ovary, then she should choose the 
opposite side to lie on; this will gravitate the ovum from 
the tube in which there would be reasons to apprehend 
a stenotic or other pathological change and which would 
retard or stop the progress of the ovum to the uterus. 
If the ovaries are in a normal condition it is always better 
to assist by gravity the ovum to the Fallopian tube of 
the ovary which matured it. The blood supply is always 
greater in the tube of the ovary which matured the 
ovum, this increased blood supply enlarges the lumen 
of the tube and allows the ovum to pass through more 
readily. Five or six hours should be ample time for 
external migration of the ovum. 
Structure of the Ovary (Figs, n, 12).-The ovary 
consists of a number of Graafian follicles embedded in 
the stroma or framework, and invested by a serous 
covering derived from the peritoneum. 
Serous Covering (Fig. 12, a).-Though the invest- 
ing membrane of the ovary is continuous with the 
peritoneum and originally derived from it, the epithelium 
of the ovarian serosa is of the short columnar variety, 
while that of the peritoneum is squamous. 
Stroma.-The stroma is a peculiar soft tissue, abun- 
dantly supplied with blood-vessels, and consists for the 
most part of spindle-shaped cells, with a small amount of 
ordinary connective tissue. These cells have been re- 
garded by some anatomists as non-striated muscle-cells, 
which they most resemble (His); by others as connective- 
tissue cells (Waldeyer, Henle, and Kolliker). On the 48 
THE CELLULAR DETERMINATION OF SEX. 
surface of the organ, this tissue is most condensed, and 
forms a layer composed of short connective-tissue fibres, 
with fusiform cells between them. This was formerly 
regarded as a distinct fibrous covering, and was termed 
the tunica albuginea, but is nothing more than a con- 
densed layer of the stroma of the ovary. The stroma 
Fig. 12.-Section of the Ovary of the Cat. V. 
a, Germ-epithelium; &, remains of egg-tubes; c, small follicle; d, more advanced 
follicle; e, discus proligerus and ovum; f, second ovum in the same follicle (this 
occurs but rarely); g, outer tunic of the follicle; h, inner tunic; i, membrana 
granulosa; k, collapsed retrograded follicle; I, blood-vessel; y, involuted portion of 
the germ-epithelium of the surface; z, place of the transition from the peritoneal 
to germinal or ovarian epithelium. 
also contains, near its attachment to the broad ligament, 
a large number of plain muscular fibres (Schafer). It is 
more than probable that these muscular fibres contract 
during orgasm, prevent the escape of blood from the 
ovary, and thus aid in rupturing the Graafian follicle at 
that moment, this being analogous to the ejectment of THE FEMALE GENERATIVE ORGANS. 
49 
semen in the male. The stroma encloses vesicles of 
different sizes, the smallest being near the surface of the 
organ, the large ones placed more deeply in the stroma, 
although, as they increase in size, they extend toward the 
surface. 
These vesicles are the Graafian follicles. Each 
Graafian follicle has a proper wall formed of a layer 
derived from the stroma, and a special inner layer con- 
taining large cells; both are highly vascular. Each 
follicle contains an ovum (Fig. 12, f, e) and epithelium. 
The fact that the largest and those most centrally located 
in the ovary are the follicles to reach maturity first, gives 
us a good reason to anticipate the maturity of the follicle 
at about the same time after each menstruation in the 
same individual in her normal condition. If the super- 
ficial follicles or those nearest the surface of the ovary 
were the ones which come earliest to maturity, then the 
time for maturity of the Graafian follicle would be 
problematical indeed. 
If maturation of the ovum began upon rupture of the 
Graafian follicle, allowing thirty minutes to each division 
of the cell for the formation of the polar bodies, it would 
consume about an hour, and this should be ample time 
for the ovum to reach the Fallopian tube after its libera- 
tion from the follicle. Then the spermatozoa will have 
had time to reach the fimbriated extremity of the 
Fallopian tube after insemination. Maturation (forma- 
tion of the polar bodies) having been completed, cell- 
division (cleavage) proceeds upon the entrance of the 
spermatozoon, without pausing a moment. 
The Corpus Luteum.-After the Graafian follicle has 
ruptured and the ovum has been set free, the corpus 50 
THE CELLULAR DETERMINATION OF SEX. 
luteum is formed. The rupture may occur either on the 
surface of the ovary or within its stroma. The follicle 
may be prevented from migrating to the surface of the 
ovary by laceration of the tunica granulosa, superinduced 
by rupture of its proper wall (theca foiliculi); by coming 
in contact with cicatricial tissue (from degenerating 
corpora lutea); or those located near the hilum, in de- 
veloping, may come in contact with it. When the 
follicle ruptures within the ovary the ovum is most sure 
to be dislodged from its normal position in the discus 
proligerus, and as the follicular secretion is taken up by 
the circulation, after a time, the ovum shrivels, dis- 
integrates, and is ultimately absorbed. When rupture of 
the follicle occurs on the surface of the ovary the ovum 
is normally extruded with the follicular secretion. Im- 
mediately after the rupture of a Graafian follicle the 
cavity is filled with a blood-tinged fluid, and in a short 
time the rupture in the wall through which the ovum 
escaped becomes closed. The cavity becomes filled with 
cells, separated into groups by trabeculae of connective 
tissue containing blood-vessels. These cells contain a 
considerable amount of yellow pigment known as lutein, 
this peculiar color having suggested its name corpus 
luteum. 
In later stages there is a gradual increase in the quan- 
tity of connective tissue and a corresponding diminution 
of the lutein cells. It gradually loses its characteristic 
color and becomes converted into a whitish, fibrous, scar- 
like body-the corpus albicans-which may eventually 
almost completely disappear. The rapidity with which 
the various stages of retrogression ensue differs according 
to whether pregnancy occurs or not, and it is customary THE FEMALE GENERATIVE ORGANS. 
51 
to distinguish the corpora lutea which are associated with 
pregnancy as corpora lutea vera from those whose ova 
fail to be fertilized and which form corpora lutea spuria. 
In the latter the retrogression of the follicle is completed 
usually in about five or six weeks, while the corpora vera 
persist throughout the duration of the pregnancy and 
complete their retrogression after parturition. 
Fig. 13.-ThEsCavity of the Uterus and 
Adjacent Structures. (Campbell.) 
A, Cavity of the uterus; B, Fallopian tube; 
C, ovary; D, ovarian ligament; E, parovarium. 
The Uterus. - The uterus 
(Figs, ii, 15) is the organ of 
gestation, receiving the fertil- 
ized ovum in its cavity, re- 
taining and supporting it during 
the development of the foetus, 
and becoming the principal agent in its expulsion at 
the time of parturition. In the virgin state it is pear- 
shaped, flattened from before backward, and situated 
in the cavity of the pelvis between the bladder and 
the rectum; it is retained in its position by the round 
and broad ligaments on each side, and projects into 52 
THE CELLULAR DETERMINATION OF SEX. 
the upper end of the vagina below. Its upper end, or 
base, is directed upward and forward; its lower end, 
or apex, downward and backward in the line of the axis 
of the inlet of the pelvis. It therefore forms an angle 
with the vagina, since the direction of the vagina corre- 
sponds to the axis of the cavity and outlet of the pelvis. 
The uterus measures about three inches in length, two 
in breadth at its upper part, and an inch in thickness, 
and it weighs from an ounce to an ounce and a half. 
The fundus is the upper broad extremity of the 
organ: it is convex, covered by peritoneum, and placed 
on a line below the level of the brim of the pelvis. 
The body gradually narrows from the fundus to the 
neck. Its anterior surface is flattened, covered by 
peritoneum in the upper three-fourths of its extent, and 
separated from the bladder by some convolutions of the 
small intestine; the lower fourth is connected to the 
bladder. Its posterior surface is convex, covered by 
peritoneum throughout, and separated from the rectum 
by some convolutions of the intestine. Its lateral mar- 
gins are concave and give attachment to the Fallopian 
tube above, the round ligament below and in front of 
this, and the ligament of the ovary behind and between 
both of these structures. 
The cervix is the lower rounded and constricted portion 
of the uterus; around its circumference is attached the 
upper end of the vagina, which extends upward a greater 
distance behind than in front. 
At the vaginal extremity of the uterus is a transverse 
aperture, the os uteri, bounded by two lips, the anterior 
of which is thick, the posterior narrow and long. 
The ligaments of the uterus are eight in number: two THE FEMALE GENERATIVE ORGANS. 
53 
anterior, two posterior, two lateral formed of peritoneum, 
and the round ligaments. 
The two anterior ligaments are two similar folds which 
pass between the neck of the uterus and the posterior 
surface of the bladder. 
Fig. 14.-The Utero-ovarian Vascular Circulation. (Campbell, after 
Robertson.) 
Shadow outline of the bladder in front. 
The two posterior ligaments pass between the side of 
the uterus and rectum. 
The two lateral or broad ligaments pass from the side 
of the uterus to the lateral walls of the pelvis, forming a 54 
THE CELLULAR DETERMINATION OF SEX. 
septum across the pelvis which divides that cavity into 
two portions. In the anterior part are contained the 
bladder, the urethra, and vagina; in the posterior part, 
the rectum. 
The cavity of the uterus (Fig. 13, A) is small in com- 
parison with the size of the organ: that portion of the 
cavity which corresponds to the body is triangular, hav- 
ing its base directed upward toward the fundus, and is 
flattened from before backward, so that its walls are 
closely approximated. At each superior angle is a 
funnel-shaped cavity which constitutes the remains of 
the division of the body of the uterus into two cornua, 
and at the bottom of each cavity is the minute orifice 
of the Fallopian tube. At the inferior angle of the 
uterine cavity is a small constricted opening, the internal 
orifice, which leads into the cavity of the cervix. The 
cavity of the cervix is somewhat fusiform, flattened from 
before backward, broader at the middle than at either 
extremity, and communicates below with the vagina. 
Each wall of the canal presents a longitudinal column, 
from which proceed a number of small oblique columns, 
giving the appearance of branches from the stem of a 
tree. 
Structure.-The uterus is composed of three coats- 
an external serous coat, a middle or muscular layer, and 
an internal mucous coat. 
The serous coat is derived from the peritoneum; it 
invests the fundus and the whole of the posterior surface 
of the body of the uterus, but only the upper three- 
fourths of its anterior surface. 
The muscular coat forms the chief bulk of the sub- 
stance of the uterus. In the unimpregnated state it is THE FEMALE GENERATIVE ORGANS. 
55 
dense, firm, of a grayish color, and cuts almost like 
cartilage. It is thick opposite the middle of the body 
and fundus, and thin at the orifices of the Fallopian 
A, Small Section of Female Generative Organs, Showing the Changed Condition 
in the very Corpulent Woman. Note the increased size of the labium majus and 
minus, also how the glans clitoridis is protected. 
B, Section of Female Pelvis, Showing Position of Viscera, a. Rectum; b, ovary; 
c, fimbriated extremity of the Fallopian tube; d, bladder; e, glans clitoridis; f, 
labium minus; g, labium majus; h, urethra; i, vagina; j, interior of rectum; k, 
anterior; I, posterior lips of os uteri; m, uterus. 
Fig. 15. 
tubes. It consists of bundles of unstriped muscular 
fibres, disposed in layers, intermixed with areolar tissue, 56 
THE CELLULAR DETERMINATION OF SEX. 
blood-vessels, lymphatic vessels, and nerves. In the 
impregnated state the muscular tissue becomes more 
prominently developed, and is disposed in three layers- 
external, middle, and internal. 
The mucous membrane is thin, smooth, and closely 
adherent to the subjacent tissue. It is continuous, 
through the fimbriated extremity of the Fallopian tubes, 
with the peritoneum, and through the os uteri with the 
mucous membrane lining the vagina. 
In the body of the uterus it is smooth, soft, of a reddish 
color, lined by columnar ciliated epithelium, and pre- 
sents, when viewed with a lens, the orifices of numerous 
tubular follicles arranged perpendicularly to the surface. 
They are of small size in the unimpregnated uterus, 
but shortly after impregnation they become enlarged, 
elongated, presenting a contorted or waved appearance 
toward their closed extremities, which occasionally 
dilate into two or three sacculated pouches. The 
circular orifices of these glands may be seen on the inner 
surface of the mucous membrane, many of which during 
the early period of pregnancy are surrounded by a 
whitish ring formed of epithelium which lines the 
follicles. In the impregnated uterus the epithelium 
looses its ciliated character. 
In the cervix (Fig. n, k) the mucous membrane be- 
tween the rugae and around the os uteri is provided with 
numerous mucous follicles and glands. The small, 
transparent, vesicular elevations so often found within 
the os and cervix uteri are due to closure of the mouths 
of these follicles and their distention with their proper 
secretion. They are called the ovula of Naboth. The 
mucous membrane covering the lower half of the cervix THE FEMALE GENERATIVE ORGANS. 
57 
presents numerous papillae, and the epithelium is strati- 
fied. 
Vessels and Nerves.-The arteries (Fig. 14) of the 
uterus are the uterine, from the internal iliac, and the 
ovarian, from the aorta. The nerves are derived from 
the inferior hypogastric and ovarian plexuses and from 
the third and fourth sacral nerves. 
Appendages of the Uterus.-The appendages of the 
uterus are the Fallopian tubes, the ovaries and their 
ligaments, and the round ligaments. 
The Fallopian Tubes. -The utero-peritoneal canal 
(Figs. 11, 13) was discovered by Fallopio Gabriello, an 
Italian anatomist, born in 1523 at Modena, and still 
bears his name. Recent observers, more especially 
Leukart, Thiersch, and Kolliker, describe the embryo- 
logical formation of these organs. 
In the walls of the Wolffian body (Figs. 1,2), situated 
near the kidneys on each side, in the female embryo, a 
narrow tube develops, which runs downward parallel 
with the excretory duct of this body, and ends below in 
the two horns of the uterus, while the distal extremity 
performs " a movement of rotation from before backward 
and from above downward; the whole, together with 
the ligaments of the ovaries and the round ligaments, be- 
ing enveloped in double folds of the peritoneum, which 
enlarge with the growth of the parts themselves, and 
constitute finally the broad ligaments of the uterus." * 
The two tubes approach each other below, and come 
together upon the median line, where they undergo 
fusion, forming the lower portion of the uterus and the 
* "Treatise on Human Physiology," by J. C. Dalton. 58 
THE CELLULAR DETERMINATION OF SEX. 
entire vagina down to the hymen. The fundal arch is 
now developed, according to Kblliker, who experimented 
on cattle, and who believes that this development occurs 
from the centre. All this occurs very early in embryonic 
life; according to Dohrn, it is completed by the second 
month. " During these changes in the adjacent organs, 
the two lateral halves of the uterus fuse with each other 
on the median line, and become covered with muscular 
fibres. In quadrupeds, the uterus remains divided for 
the most part into two long conical tubes or cornua. 
In the human species, the fusion between the lateral 
halves of the organ is nearly complete; so that the uterus 
presents externally a rounded, flattened, and somewhat 
triangular figure, with the ligaments of the ovary and 
the round ligaments passing off from its upper corners. 
Internally, its cavity still presents a strongly marked 
triangular form, the vestige of its original division. 
Occasionally the human uterus remains divided inter- 
nally by a vertical septum, running from the middle of 
its fundus toward the os internum. It may even present 
a partial external division, corresponding to the situation 
of the septum, and producing the malformation known as 
uterus bicornis or double uterus. 
" The Fallopian tubes or oviducts are two in number, 
one on each side, situated in the upper margin of the 
broad ligament, extending from each superior angle of 
the uterus to the sides of the pelvis. Each tube is about 
four inches and a quarter in length, and is placed in a 
fold of peritoneum, which is part of the broad ligament 
and is called the mesosalpinx. Each tube is described 
as consisting of three portions: (i) the isthmus, or 
inner constricted third; (2) the ampulla, or outer THE FEMALE GENERATIVE ORGANS. 
59 
dilated portion, which curves over the ovary; and (3) 
the infundibulum, the funnel-like expansion of the tube, 
at the bottom of which is the abdominal orifice or 
pavilion. The abdominal orifice has a small diameter 
(2 mm. when relaxed to its full extent). The margin of 
the infundibulum is rendered irregular by the presence 
of numerous small processes (Fig. 11, d), the fimbriae. 
The surfaces of the fimbriae looking into the cavity of 
the infundibulum are covered with mucous membrane 
continuous with the tubal mucous membrane. The 
outer surfaces are covered with peritoneum. One of the 
fimbriae (Fig. 11, e) is attached to the ovary and is called 
the ovarian fimbria. The uterine portion of the tube is 
in the uterine wall. The opening in the uterus is even 
smaller than the abdominal opening, and will admit 
only a small bristle. The general direction of the 
Fallopian tube is outward, backward, and downward. 
In connection with the fimbriae of the Fallopian tube, 
or with the broad ligament close to them, there is 
frequently one or more small vesicles floating on a long 
stalk of peritoneum. They are representative of small 
portions of the upper extremity of the Wolffian duct" 
(Gray). 
Course Pursued by the Fallopian Tube.-The tube 
on each side begins at the upper and outer angle of the 
uterus and passes outward in a horizontal direction 
toward the uterine extremity of the ovary. It then 
bends almost at a right angle and ascends close to the 
pelvic wall and in front of the anterior margin to the 
tubal extremity of the ovary. At this point it turns 
sharply downward and a little backward, and the inner 
surface of the infundibulum comes to lie upon the free 60 
THE CELLULAR DETERMINATION OF SEX. 
margin and the posterior portion of the inner surface of 
the ovary (Fig. n, b). 
Structure.-The Fallopian tube consists of three 
coats-serous, muscular, and mucous. 
The external or serous coat is peritoneal. Beneath 
this lies the tunica adventitia, composed of lax connective 
tissue. 
The middle or muscular coat consists of an external 
longitudinal layer, and an internal circular layer of 
plain muscular fibres continuous with those of the 
uterus. 
The internal or mucous coat is continuous with the 
mucous lining of the uterus and, at the free extremity 
of the tube, with the peritoneum. It is thrown into 
longitudinal folds, which, in the outer, large part of the 
tube or ampulla, are much more extensive than in the 
narrow canal of the isthmus. The lining epithelium is 
columnar and ciliated. This form of epithelium is also 
found on the inner surface of the fimbriae, while on the 
outer or serous surface of the processes the epithelium 
gradually merges into the endothelium of the peritoneum. 
The organ of Rosenmuller is placed in the mesosalpinx, 
between the ovary and tube (Fig. n, n). It consists of a 
number of epithelium-lined closed tubes. This structure 
can be readily seen if the mesosalpinx is stretched and 
held in front of the light. One of these tubes runs 
parallel to the Fallopian tube and is called Gartner's 
duct. A number of tubes ascend from near the ovary 
and each empties into Gartner's duct at a right angle. 
Gartner's duct is a portion of the Wolffian duct, which 
has perished and is represented in the male by the canal 
of the epididymis. The tubules which join the duct are THE FEMALE GENERATIVE ORGANS. 
61 
derived from the mesonephros and represent the vasa 
efferentia and coni vasculosi of the testis, and probably 
also the ductuli aberrantes of the canal of the epididymis. 
The paroophoron is within the mesosalpinx, but is nearer 
to the uterus than is the organ of Rosenmuller. It 
consists of several small tubules, which can be seen in 
an adult only by the aid of a pocket lens. They are 
visible to the naked eye in a child at birth. It repre- 
sents the organ of Giraldes in the male and is derived 
from the mesonephros. 
The chief artery of the Fallopian tube is the tubal 
branch of the uterine artery. It also receives branches 
from the ovarian. Some of the tubal veins empty into 
the uterine veins, some into the ovarian veins. The 
lymphatics coming from the tube unite with the trunks 
coming from the uterus and ovary and terminate in the 
juxta-aortic gland. The nerves come from the same 
plexuses that send branches to the uterus and ovary. 
Function.-The function of the Fallopian tubes varies 
in different animals. The mucous membrane of the 
Fallopian tubes in the lower animals is usually adapted 
for supplying certain secretions during the passage of 
the egg, which secretions complete its formation. In 
the frog, the Fallopian tube commences at the upper 
part of the abdomen, by a rather wide orifice, which 
communicates with the peritoneal cavity. It then 
contracts abruptly to a narrow tube, which is lengthened 
by folding upon itself in numerous convolutions, until 
it opens, near its fellow of the opposite side, into that 
part of the intestinal canal known as the cloaca. This 
is also the general character of the oviducts in nearly 
all reptiles and birds; the birds have but one oviduct; 62 
THE CELLULAR DETERMINATION OF SEX. 
the right oviduct with the corresponding ovary atrophies 
in early embryonic life. 
"In the frog, after the ripening of the eggs and their 
discharge from the ovarian follicles, they receive an 
additional investment in the oviducts. On leaving the 
ovary, they consist only of the dark-colored vitellus, 
enclosed in its vitelline membrane. Their passage 
through the oviduct is effected by the peristaltic con- 
traction of its walls, aided by the abdominal muscles. 
During this passage, an albuminous substance, secreted 
by the oviduct, is deposited round each egg in successive 
layers, forming a thick envelope. When the eggs are 
discharged, they absorb moisture from the water in which 
they are deposited, and swell into a transparent mass, 
in which the eggs are embedded. By its subsequent 
liquefaction and absorption, it supplies material for the 
nourishment of the embryo. The frog's eggs are fer- 
tilized after they pass through the Fallopian tube. In 
birds and scaly reptiles, the Fallopian tube performs a 
more important function; the spermatozoa pass through 
its lumen to the ovary, where fertilization of the ovum 
takes place before its extrusion from the Graafian follicle; 
and several membranes are added to the vitellus during 
its passage through the Fallopian tube.'' 
The ovum of the bird is fertilized while it is yet in the 
ovary. The spermatozoa have very little resistance to 
overcome in penetrating the covering membranes of the 
egg, for they are distended to their fullest capacity by 
the ovum itself, until they are so thin and delicate as 
to be very readily pierced by the spermatozoa. In 
Dalton's beautiful description of the female generative 
organs of the bird he says: " In scaly reptiles and birds, THE FEMALE GENERATIVE ORGANS. 
63 
the oviducts perform a more important function. In 
the common fowl, the ovary consists of follicles of various 
size, loosely united by connective tissue, and containing 
eggs in different stages of development. As the egg 
which is approaching maturity enlarges, it distends its 
follicle, and projects from the general surface of the 
ovary; so that it hangs at last into the peritoneal 
cavity, retained only by the attenuated wall of the 
follicle, and a slender pedicle containing its blood- 
vessels. A rupture of the follicle then occurs at its 
most prominent part, and the egg is discharged from 
the lacerated opening. As the egg leaves the ovary, it 
consists of a large, globular, orange-colored vitellus, or 
' yolk,' enclosed in a thin transparent vitelline membrane. 
Immediately beneath the vitelline membrane, on the 
surface of the vitellus, is a round white spot, consisting 
of a layer of minute granules, termed the ' cicatricula,' in 
which the germinative vesicle was previously embedded. 
At this time the germinative vesicle has usually disap- 
peared; but the cicatricula is still an important part of 
the vitellus, and marks the spot from which the embryo 
begins its development. From the surface of the ovary, 
the yolk projects into the orifice of the oviduct; and 
when discharged from its follicle, it is embraced by the 
extended upper extremity of this tube, and commences 
its downward passage. 
" In the fowl, the muscular coat of the oviduct is highly 
developed, and its peristaltic contractions urge the egg 
from above downward, somewhat as the oesophagus or 
the intestine transports the food in a similar direction. 
While passing through the first 5 or 6 centimetres of 
the oviduct, where the mucous membrane is smooth 64 
THE CELLULAR DETERMINATION OF SEX. 
and transparent, the yolk absorbs a certain quantity of 
fluid, becoming consequently softer and more flexible. 
It then passes into a second division of the canal, in 
which the mucous membrane is thicker and more 
globular in texture, and arranged in longitudinal folds. 
This portion extends over about 22 centimetres, or more 
than one-half the length of the oviduct. In its upper 
part, it secretes a viscid material, which consolidates 
into a gelatinous deposit around the yolk, thus forming 
a second envelope, outside the vitelline membrane. The 
peristaltic movements of the oviduct are such as to give 
a rotary, as well as a progressive motion to the egg; 
and by this means the two extremities of the gelatinous 
envelope become twisted in opposite directions, forming 
rope-like extensions at the two poles of the egg. They 
are termed the ' chalazae,' or suspensory cords, and the 
membrane with which they are connected is the ' chala- 
ziferous membrane.' 
" Throughout the remainder of this part of the 
oviduct, an albuminous substance is deposited in suc- 
cessive layers around the yolk, including the chala- 
ziferous membrane and chalazae. This substance, the 
so-called albumen, or ' white of egg,' is gelatinous in 
consistency, nearly transparent, and of a faint amber 
color. It is deposited in greater abundance in front of 
the egg than behind it, and thus forms a conical pro- 
jection anteriorly, while behind, its outline is parallel 
with the spherical surface of the yolk. In this way, the 
egg acquires, when covered with its albumen, an ovoid 
form, of which one end is round, the other pointed; the 
pointed extremity being directed downward, as the egg 
descends through the oviduct. THE FEMALE GENERATIVE ORGANS. 
65 
" In the third division of the oviduct, which is about 
9 centimetres in length, the longitudinal folds of the 
mucous membrane are narrower and more closely packed 
than in the preceding portion. Its secretion condenses 
into a fibrous covering, composed of three layers, closely 
embracing the surface of the albuminous mass, and 
forming a tough, flexible, semi-opaque envelope for the 
whole. These layers are known as the external, middle, 
and internal fibrous membranes. 
" Finally the egg passes into the fourth division of 
the oviduct, which is wider than the rest of the canal, 
but only a little over 5 centimetres in length. Its 
mucous membrane, which is covered with abundant 
leaf-like villosities, exudes a fluid rich in calcareous salts. 
The external fibrous layer is permeated by this secretion; 
and afterward, owing to the reabsorption of fluid, the 
calcareous matter is deposited in its network. The 
deposit goes on, growing thicker and more condensed, 
until the membrane is converted into a white, opaque, 
brittle, calcareous shell. The egg is then forced through a 
narrow portion of the oviduct, and, gradually dilating 
the passages by its conical extremity, is discharged from 
the external orifice." 
In mammals the Fallopian tube is the ideal place for 
select fertilization, and it may take place at any point 
in the tube, the nearer the fimbriated extremity the 
greater the endurance and the better the selection of the 
spermatozoon. If rupture of the Graafian follicle took 
place during insemination, the spermatozoa would be 
able to meet the ovum near the fimbriated extremity of 
the tube, when fertilization would take place and cell 
division would begin immediately. The passage of the 66 
THE CELLULAR DETERMINATION OF SEX. 
ovum through the Fallopian tube should not consume 
more than three hours. It is hard to understand how 
so many have arrived at the estimation of eight days as 
the time required for the ovum to' pass through the 
Fallopian tube, when we know how rapidly all kinds of 
foreign matter are eliminated from the lung by the same 
kind of membrane and over twice the distance in less 
than half the time above given (three hours). Fertiliza- 
tion of the ovum in the human ovary may take place 
only when the ovum remains in the Graafian follicle 
after its rupture, the spermatozoon gaining entrance 
through the rent made by the rupture. In the human 
species it is a matter of impossibility for the spermatozoon 
with its large club-shaped acrosomeless head to penetrate 
the three tunics (ovarian envelope, membrana granulosa, 
and discus proligerus) and fertilize the ovum. Ovarian 
fertilization is most undesirable, for it causes the in- 
evitable death of the foetus, and great danger to the life 
of the mother. Fertilization may take place in the 
peritoneal cavity and yet the ovum find its way to the 
fimbriated extremity of the Fallopian tube where it 
would be picked up and wafted through the tube to 
the uterus where pregnancy proceeds normally. Or 
fertilization may take place in the uterine cavity; but 
this is undesirable for the reason that fertilization erf the 
ovum is limited only to the power necessary for the 
spermatozoon to enter the uterus and penetrate the 
vitelline membrane of the ovum. 
The movements of the cilia could not be a great bar- 
rier to the progress of the spermatozoa, but the current 
set up in the mucous secretion is to be overcome by them 
without ceasing. The constant struggle necessary to THE FEMALE GENERATIVE ORGANS. 
67 
maintain a position in any part of the Fallopian tubes 
soon reduces the largest and best male-producing 
spermatozoa to female-producing by consuming the 
nutriment stored up in the nucleus. The old, inactive, 
and decrepit spermatozoa are wafted back into the 
uterine cavity and from there to the vagina. 
In the above-described mechanism, we see nature 
selecting the most active specimen of the spermatozoa 
for propagation. In the production of a male, the most 
active spermatozoon, be it large or small, of little or 
great endurance, will stand the same chance to fertilize 
the ovum as the large and those more capable of a greater 
endurance. This condition of male-production gives 
rise to the greater variation in size and endurance of the 
male. Where there is a delay of the ovum to arrive, and 
this is often the case, the male-producing spermatozoon 
becomes female-producing. Here we see the best tested 
spermatozoa producing the female, giving to her greater 
uniformity in size and endurance. This would indicate 
that the female uniformly should have just a little 
greater endurance than the male, and the truth of this 
law is shown in my statistics as given in which the 
mortality is thirteen per cent greater in the male in the 
aggregate mortality of five hundred and seventy-seven 
children under five years of age. Mr. Charles Dar- 
win mentions this fact in the " Descent of Man," Part 
II., Sexual Selection, Chapter VIII., in which he says: 
" It is a well ascertained fact that with man the num- 
ber of males dying before or during birth and during 
the first few years of infancy is considerably larger 
than that of females. So it almost certainly is with 
male lambs, and probably with some other animals." 68 
THE CELLULAR DETERMINATION OF SEX. 
In this case an author has made this statement from 
facts deduced from a record of millions of children and 
not hundreds as I have given. My statistics only go 
to confirm this law for which Mr. Darwin was unable 
to give a tenable answer or cause. 
" The International Clinics," Vol. II., 21st Series: 
In Montgomery's article on the cellular basis of the 
determination of sex, where this law is noted, we find 
the following: "And it may also be noted that the nu- 
merical ratio of the sexes is not always 1 : 1 as generally 
assumed, even where there are separated males and 
females in the same generation. Thus in 10,864,950 
human births there were found 103.6 males to 100 
females (Pike, 1907), and for ' still-born infants, fully 
formed but not alive,' Quetelet found 133.5 males to 100 
females (Morgan, 1907)." 
In the quadrupeds and man, there is a further modifi- 
cation of the oviducts. They serve two purposes: they 
furnish an ideal field for fertilization of the ovum, 
and convey the minute, motionless ovum from the 
reproductive glands to the uterus for development. It 
is claimed by some that the ova receive a small quantity 
of albuminous secretion during their passage through 
the lumen of the oviducts to the uterus,-this is true only 
after fertilization takes place and cell division has begun. 
The ovum is immersed for many days before its extrusion 
from the Graafian follicle in an albuminous secretion, 
which is wafted along with it into the uterine cavity. 
When the normal ovum leaves the Graafian follicle, it 
has absorbed all it is capable of absorbing until cell 
division begins. There is nothing lost on account of 
its passage through the Fallopian tube. There is no THE FEMALE GENERATIVE ORGANS. 
69 
motion on its part to consume anything, which is true 
of all ova of both the vertebrate and the invertebrate 
animals. The lumen of the oviduct and the cavity of 
the uterus of all mammals are lined with ciliated 
epithelium, the motion of which produces a current in 
the mucous secretion from the ovary to the uterus, and 
from the uterus to the vagina. The vigorous lashing, 
whip-like movements of the cilia are so rapid and the 
ryhthm is so frequent (twelve or more times a second), 
that it is hard to follow the motion with the eye. This 
vigorous motion of the cilia produces such a rapid current 
in the fluid contents of the tube, that the deformed, the 
weak, and the decrepit spermatozoa are wafted back 
into the uterus and from there into the vagina, as soon 
as they are unfit for fertilization. The minute orifice 
of the Fallopian tube at the uterine extremity serves to 
increase the current of the mucous secretion through this 
part of the tube, and this rapidity renders it more difficult 
for the spermatozoa to enter the Fallopian tubes in the 
contest for fertilization; and, after they enter the tubes, 
they are continually put to the test by the constant 
current set up in the mucous secretion by the ceaseless 
motion of the cilia. In this we see nature's most beauti- 
ful mechanism for selecting the fittest of these micro- 
scopic living organisms (called spermatozoa) for propaga- 
tion. It is this mechanism that selects the most active, 
and goes far to secure for fertilization the best, strongest, 
and most vigorous spermatozoa present. 
In studying a microscopic field of a specimen of semen, 
recently removed from the vesiculae seminales, we see 
one or two intensely active spermatozoa, while there are 
a hundred or more moving normally. On closer exam- 70 
THE CELLULAR DETERMINATION OF SEX. 
ination of these active spermatozoa their nucleus is 
found to be very small, and they would ordinarily be 
classed as female-producing spermatozoa. When such a 
spermatozoon reaches the ovum, it will dash through the 
vitelline membrane into the cytoplasm, entering with 
both body and tail, and thus produce a male. This 
result is due to the intense rapidity of its movements. 
The male produced from such an ultra-active spermato- 
zoon is defective, weak, and delicate, and this fact may 
account for the great mortality among male children, 
which is one hundred and thirty-three male to one 
hundred female under five years of age. The sooner 
fertilization takes place after the ovum enters the 
Fallopian tubes, the better, and the greater is the chance 
for a strong active spermatozoon. It is only the 
strongest and most active spermatozoa that make their 
way to the ovarian extremity of the Fallopian tubes. 
Fertilization of the ovum in the uterus is most undesir- 
able, for the reason that the spermatozoa there found 
may have been too weak to undergo the severe test of 
passing through the Fallopian tubes. Should fertilization 
take place in the uterine cavity, the ovum is liable to be 
wafted out into the vagina before it can attach itself, 
or toward the lower part of the uterus, where it produces 
a condition known as placenta praevia. It is necessary 
for cell division of the ovum to be in rapid progress, that 
the more fluid constituents of the mucus be taken up, 
and that viscid constituents which serve to fix the 
fertilized ovum be left without. As soon as the mucus 
immediately surrounding the ovum becomes viscid 
through absorption from within the ovum, the cilia 
adhere to it, and further migration of the ovum ceases. THE FEMALE GENERATIVE ORGANS. 
71 
It is not necessary for the ovum to be wafted into a 
depression in order to become fixed; it is probable that 
it becomes attached to an eminence in the wall of the 
uterus more often than to a depression. 
The conveyance of the ovule through the Fallopian 
tube is accomplished by the movement of the cilia, which 
takes up the fluid of the ruptured Graafian follicle in 
which the ovule is immersed, and wafts them both into 
the uterine cavity. The time consumed in the passage 
of the ovule through the Fallopian tube has been vari- 
ously estimated: Barnes gives eight days and longer; 
Parvin says, " some time intervenes between coition 
and conception, between insemination and impregnation; 
this interval possibly is some hours, and it may be, as 
illustrated by the fecundation of the hen's egg twelve 
days before it is laid, several days." Inasmuch as 
fertilization of the bird's egg takes place before it leaves 
the Graafian follicle, the comparison of it to that of the 
human female is without weight, because the human 
ovule is never fertilized until after its extrusion from the 
Graafian follicle. In the human species six hours should 
be considereded a prolonged time, while three hours are 
scarcely ever consumed in the conveyance of the ovule 
through the Fallopian tube. It is probable that this is 
accomplished in less than two hours in the majority 
of cases. This may be determined with reasonable 
accuracy by comparing the movement of foreign matter 
wafted through the bronchial tubes, with that obtained 
in the Fallopian tubes. Both are lined with ciliated 
epithelium, but the bronchial tubes are twice the length 
of the oviducts. Thus the oviducts are favored in 
both power and rapidity for moving foreign substances 72 
THE CELLULAR DETERMINATION OF SEX. 
through them. When a foreign substance is wafted 
through the oviducts, it is encompassed by the cilia, 
whose movements are ceaseless until it is eliminated. 
When the cilia fail to move it, the peristaltic action of 
the duct is set up, which augments the onward move- 
ment. The bronchial tubes arc hollow cylinders, lined 
with ciliated epithelium. A foreign substance in the 
lung is immersed in mucus and wafted along the sides 
of the bronchial tubes with the disadvantage of the dry- 
ing effect of the air-current through the tubes. Still we 
would consider six hours a very long time for a foreign 
substance to be wafted from the remotest part of the. 
lung to the larynx. 
Diseases of the Fallopian Tubes.-Reproduction of 
all mammals is dependent upon the maintenance of the 
lumen in the Fallopian tubes, and their ability to take 
up and convey the ovula from the ovary to the uterine 
cavity. The human is the only species of the mammalian 
group of animals subject to disease of the Fallopian 
tubes, caused by gonorrhoeal or septic infection, the 
latter occurring after labor, or following the introduction 
of septic instruments into the uterus. A purulent 
salpingitis may run a chronic course of a catarrhal type, 
simply thickening the walls of the tubes and causing the 
formation of adhesions about them, the tubes remaining 
patent and draining into the uterus, and a purulent 
endometritis being associated with the tubal disease. 
More commonly, the connection with the uterus is 
obstructed, although the uterine end is never completely 
closed, and the tube is distended by the accumulating 
purulent secretion. The open end of the tube at the 
fimbriated extremity is closed very early by adhesions, THE FEMALE GENERATIVE ORGANS. 
73 
and the result is a pus sac formed by the distended and 
usually convoluted walls of the tube which are firmly 
adherent to all the parts about it, and especially to the 
ovary (pyosalpinx). In milder cases the disease may not 
progress so far as to produce a pus sac, but may cause 
obliteration of the uterine extremity of the tube, and 
then blood or serum may collect in the latter. In the 
former case we have haematosalpinx, in the latter 
hydrosalpinx. The inflammation may involve the 
ovary also, forming an abscess the cavity of which may 
communicate with that of the tube. These tubo- 
ovarian inflammatory cysts may also originate from the 
union of a pyosalpinx or hydrosalpinx with an ovary 
already in a cystic condition. The connection between 
the two may be the orifice of the tube or an abnormal 
lateral opening. In connection with inflammation of 
the tubes, abscesses are occasionally found in the pelvis 
developing in the peritoneal cavity or in the cellular 
tissue, or involving the ovary (Wharton and Curtis, 3d 
ed.). Any pathological condition or malformation of 
the tubes which prevents the passage of the ovule to the 
uterus, but which does not prevent the spermatozoa 
from passing to the ovule, may produce extra-uterine 
pregnancy. Women whose reproductive organs have 
never been subject to gonorrhoeal or septic infection 
give the best promise of sex control. 
The Vagina (Figs. 11, a, 13, 15) is a membranous canal, 
from three to six inches long, extending in a curve down- 
ward and forward from the neck of the uterus, which 
it embraces, to the external organs of generation. Its 
lining membrane is covered with stratified squamous 
epithelium, and contains a number of mucous crypts, 74 
THE CELLULAR DETERMINATION OF SEX. 
but no true glands. External to the lining membrane, 
the walls of the vagina are constructed of plain muscle 
and fibrous tissue, within which in the submucosa, more 
especially around the lower part of the tube, is a layer 
of erectile tissue. The erectile tissue exists also in the 
mucosa. The lower extremity of the vagina is sur- 
rounded by a band of striated muscular fibres, the 
sphincter vaginae; its external orifice, when unruptured, 
is partially closed by a fold of mucous membrane, called 
the hymen. The mucous secretion of the vagina is acid 
in reaction, which is destructive to the spermatozoa. 
Although this is true, there are " occasional cases of 
pregnancy in which conception occurs through a minute 
opening and an almost imperforate hymen, and also one 
recorded case in which no apparent opening existed " 
(Edgar). The sexual union produces a flow of mucus 
from the mucous crypts in the wall of the vagina, through 
which the spermatozoa pass to the uterus before this 
mucus becomes acid in reaction. It is impossible for 
the human spermatozoa to pierce the normal mucous 
membrane. 
"The external organs of generation in the female are 
the mons veneris, the labia majora and minora, the 
clitoris, the meatus urinarius, and the orifice of the 
vagina. The term 'vulva' or 'pudendum,' as generally 
applied, includes all these parts. 
"The mons veneris is the rounded eminence in front of 
the pubes formed by a collection of fatty tissue beneath 
the integument. It surmounts the vulva and becomes 
covered with hair at the time of puberty. 
"The labia majora are two prominent longitudinal 
cutaneous folds extending downward from the mons THE FEMALE GENERATIVE ORGANS. 
75 
veneris to the anterior boundary of the perineum, and 
enclosing an elliptical fissure, the common urino-sexual 
opening. Each labium is formed externally of integu- 
ment covered with hair; internally, of mucous mem- 
brane, which is continuous with the genito-urinary 
mucous tract; and, between the two, of a considerable 
quantity of areolar tissue, fat, and a tissue resembling 
the dartos of the scrotum, besides vessels, nerves, and 
glands. The labia are thicker in front than behind, and 
ioined together at each extremity, forming the anterior 
and posterior commissures. The interval left between 
the posterior commissure and the margin of the anus is 
about an inch in length, and constitutes the perineum. 
Just within the posterior commissure is a small trans- 
verse fold, the fraenulum pudendi or fourchette, which is 
commonly ruptured in the first parturition, and the space 
between it and the commissure is called the fossa navi- 
cularis. The labia are analogous to the scrotum in the 
male. 
"The labia minora or nymphae are two small folds of 
mucous membrane situated within the labia majora, 
extending from the clitoris obliquely downward and out- 
ward for about an inch and a half on each side of the 
orifice of the vagina, on the sides of which they are lost. 
They are continuous externally with the labia majora, 
internally with the inner surface of the vagina. As they 
converge toward the clitoris in front each labium divides 
into two folds, which surround the glans clitoridis, the 
superior folds uniting to form the praeputium clitoridis, 
the inferior folds being attached to the glans and forming 
the fraenum. The nymphae are composed of mucous 
membrane, covered by a thin epithelial layer. They 76 
THE CELLULAR DETERMINATION OF SEX. 
contain a plexus of vessels in their interior, and are pro- 
vided with numerous large mucous crypts which secrete 
abundance of sebaceous matter. 
"The hymen is a thin semilunar fold of mucous mem- 
brane stretched across the lower part of the orifice of the 
vagina, its concave margin being turned upward toward 
the pubes. Sometimes this membrane forms a complete 
septum across the orifice of the vagina-a condition 
known as imperforate hymen. Occasionally it forms a 
circular septum, perforated in the centre by a round 
opening; sometimes it is cribriform, or its free margin 
forms a membranous fringe, or it may be entirely absent. 
It may also persist after copulation. The hymen can- 
not, consequently, be considered as a test of virginity. 
Its rupture or the rudimentary condition of the mem- 
brane above referred to gives rise to those small rounded 
elevations which surround the opening of the vagina, 
the carunculae myrtiformes. 
" Glands of Bartholin.-On each side of the commence- 
ment of the vagina is a round or oblong body, of a red- 
dish-yellow color and of the size of a horse-bean, analo- 
gous to Cowper's gland in the male. It is called the 
gland of Bartholin. Each gland opens by means of a 
long single duct upon the inner side of the nymphae, 
external to the hymen. (Occasionally these become 
inflamed or obstructed and cause retention-cysts or 
abscesses.) 
"The clitoris is an erectile structure analogous to the 
corpora cavernosa of the penis. (It differs from the 
penis in having no corpus spongiosum and no urethra.) 
It is situated beneath the anterior commissure, partially 
hidden between the anterior extremities of the labia THE FEMALE GENERATIVE ORGANS. 
77 
minora. It is an elongated organ, connected to the 
rami of the pubes and ischia on each side by a crus; the 
body is short and concealed beneath the labia; the free 
extremity, or glans clitoridis, is a small rounded tubercle 
consisting of spongy erectile tissue and highly sensitive. 
The clitoris consists of two corpora cavernosa composed 
of erectile tissue enclosed in a dense layer of fibrous 
membrane, united together along their inner surfaces by 
an incomplete fibrous pectiniform septum. It is pro- 
vided, like the penis, with a suspensory ligament and 
with two small muscles, the erectores clitoridis, which are 
inserted into the crura of the corpora cavernosa. 
"Between the clitoris and the entrance of the vagina 
is a triangular smooth surface bounded on each side by 
the nymphae; this is the vestibule. 
"The orifice of the urethra (meatus urinarius) is situ- 
ated at the back part of the vestibule, about an inch 
below the clitoris and near the margin of the vagina, 
surrounded by a prominent elevation of the mucous 
membrane. Below the meatus urinarius is the orifice of 
the vagina, an elliptical aperture, more or less closed in 
the virgin by a membranous fold, the hymen.'' (Gray.) 
It is necessary for the male organ to come into con- 
tact with the clitoris during the sexual union to produce 
orgasm in the female. This fact explains why some 
women remain in an apathetic condition during the 
sexual union, neither the body nor the glans being erect, 
and their erection is necessary before the sexual shock 
can be delivered. When it is desirable to rupture a 
Graafian follicle, the glans clitoridis must be erect, and 
this condition is present only in those women who are 
passionate, loving, and fond of their husbands. 78 
THE CELLULAR DETERMINATION OF SEX. 
In the very fleshy women (Fig. 15, A, e), a considerable 
quantity of fat is stored in the tissue adjacent to the 
clitoris, which prevents the male organ from coming in 
contact with it during the sexual union. When this is 
the case it prevents orgasm in the female and there is a 
consequent excessive production of girls or sterility. CHAPTER IV. 
THE SPERMATOZOON. 
The Human Spermatozoon.-Each spermatozoon 
consists of three parts: a head, a middle part or body, 
and a long, slender, tapering tail (Figs. 16, 17). The 
heads are of several sizes and shapes, varying according 
to age: in the young, large and round; in the old, small 
and oval. The head, or nucleus, of the spermatozoon 
is clear whitish in appearance and remains so until 
disintegration takes place, unless it is stained by some 
reagent. It is covered with a very thin cytoplasmic 
envelope, the posterior part of which is overlapped by 
the sex membrane, to be described later. It represents 
the modified nucleus of the spermatid, and consists 
chiefly of chromatin, and so stains readily with nuclear re- 
agents. The nucleus of the human spermatozoon is made 
up of granules arranged concentrically (Fig. 18, I, II, b). 
In some animals it bears a small barb-like projection, the 
acrosome, at its anterior extremity, by means of which 
the spermatozoon bores its way into the ovum. The 
acrosome in some animals is at times almost as large as 
the nucleus, while in others it is very minute, and in 
man it seems to be absent. The head of a normal 
spermatozoon, which has just become detached from 
the mother cell, or the large cell of Sertoli (Fig. 16, I), 
is very large and is almost perfectly round, being more 
elliptical in profile than those to be described later. In 
79 80 
THE CELLULAR DETERMINATION OF SEX. 
Fig. 16.-Human Spermatozoa on the Flat and in Profile. 
n, The nucleus or head; sm, sex-membrane; b, body; t, tail; e.p, end-piece. 
These are male-producing spermatozoa, those to the left are more decidedly so. 
Only the commencement of the tail is represented in the two which are shown in 
profile, i, Upper surface; 2, lower surface. Note the convexity of the upper 
surface, and the concavity of the lower. Magnified 2,500 diameters. THE SPERMATOZOON. 
81 
n. Nucleus or head; sm, sex-membrane; b, body; t, tail; e.p, end-piece. These 
are female-producing spermatozoa. Only the commencement of the tail is repre- 
sented in the two which are shown in profile. I, Upper surface; 2, lower surface. 
Note the convexity of the upper surface, and the concavity of the lower. Magnified 
2,500 diameters. 
Fig. 17.-Human Spermatozoa on the Flat and in Profile 82 
THE CELLULAR DETERMINATION OF SEX. 
semen which has been allowed to accumulate in the 
vesiculae seminales for eight or ten days, we find a number 
of spermatozoa, some dead, some just able to move, 
which on examination show the head to be much smaller 
(Fig. 17, I, II) than those above described. The antero- 
posterior diameter is shorter, the head is oval in shape, 
almost pointed anteriorly, in profile (Fig. 17, I, II) it 
is narrow and pointed at its free end, and the sex-mem- 
brane apparently runs farther up and covers more of 
the anterior part of the head, from one-half to three- 
fourths or more of its surface. This is not the case in 
the young spermatozoon. The sex-membrane to which 
I refer above is not described by others. 
The sex-membrane (Figs. 16, 17, sm) is a thin enve- 
lope, covering and fitting perfectly the posterior one- 
fourth to four-fifths of the nucleus of the human sperma- 
tozoon. This membrane is continuous with and covers 
the body or middle-piece, tail, and end-piece. It fits 
over the posterior part of the nucleus like the cup over 
the acorn. The head, or nucleus, of the spermatozoon 
contains the nutriment from which the spermatozoon is 
fed during its life. As the spermatozoon grows old or 
begins to move about, this nutriment is gradually used 
up, with a consequent shrinking of the head. The 
protoplasm stored in the nucleus of the spermatozoon is 
the constituent consumed and not the chromatin. In 
some the body near the head then looks as if it were 
pyramidal in shape, but the appearance is due to the 
shrinking of the sex-membrane to the smaller nucleus. 
At the same time the membrane will reach farther for- 
ward toward the free end of the nucleus and thus cover 
more of the nucleus when it becomes old and small. THE SPERMATOZOON. 
83 
The sex-membrane maintains its size from the time 
the spermatozoon becomes detached from the Sertoli cell 
until the death of the spermatozoon. This membrane 
is derived from the unmodified cytoplasm of the sperma- 
tid, and is held in position by a viscid substance, by at 
least three of the axial filaments (Fig. 18, a) which pass 
into the substance of the nucleus and may be given 
Fig. 18.-The Nucleus of a Human Spermatozoon. 
I, Nucleus of the spermatozoon with the sex-membrane removed. Note the 
three openings from which the axial filaments were extracted, a, Opening made 
by the extraction of one of the axial filaments; b, laceration of the nucleus from 
the extraction of the filament. II, The laceration highly magnified. Note the 
concentrical arrangement of the layers of the nuclear substance and their division 
into sections. 
off from the end-knobs in the anterior part of the body, 
by its very slight contractility, and by its perfect prox- 
imity to the thin, dense, smooth, whitish, clear, cyto- 
plasmic envelope of the nucleus. When the nucleus is 
dislodged from the sex-membrane, it is perfectly smooth 
and uniform in contour, and no part or particle of the 
sex-membrane remains attached to it. The inner surface 
of the sex-membrane which comes into contact with the 84 
THE CELLULAR DETERMINATION OF SEX. 
Fig. 19.-Human Spermatozoa. 
Showing detachment of the nucleus, sm., Sex-membrane, with the nucleus 
detached; b, body; t, tail; e.p, end-piece. Magnified 2,000 diameters. THE SPERMATOZOON. 
85 
Fig. 20.-Human Spermatozoon. 
Fig. 2i.-Human Spermatozoon. 
Fig. 20.-Sex-membrane pushed back on the nucleus, n, Nucleus; sm, sex- 
membrane, pushed back from one side of the nucleus; b, body; t, tail; e.p, end-piece. 
Fig. 2i.-n. Nucleus, left axial filament broken, causing its deflection to the right; 
s,m, sex-membrane; b, body; I, tail; e.p, end-piece. 86 
THE CELLULAR DETERMINATION OF SEX. 
nucleus is somewhat granular in appearance; it is not so 
smooth and homogeneous as it is on the outside. The 
sex-membrane does not collapse in every case when the 
nucleus is removed from it, but the peripheral border 
sometimes rolls back very slightly (Fig. 19, II). In 
some cases it will partially collapse, as shown in Fig. 
19, 
This membrane is occasionally pushed back on the 
nucleus, as shown in Fig. 20. As soon as one of the 
axial filaments which pass from the end-knob into the 
nucleus is broken or detached from the inner structure 
of the nucleus, all motion ceases. The breakage may 
be due to the spermatozoon trying to enter a hard sub- 
stance, or striking it with its head; in such a case the 
nucleus is deflected from the side of the detached or 
broken filament (Fig. 21), but still remains in the sex- 
membrane. The sex-membrane is not conspicuous in 
the living spermatozoa, but becomes so from twelve to 
eighteen hours after their death, when it assumes a 
yellowish-green color, and is seen to be continuous with 
the covering of the body and tail. The sex-membrane 
is subject to the same changes from reagents as the ex- 
ternal envelope of the body and tail. 
The staining is more decided in the nucleus immediate- 
ly under this membrane, and is caused by capillary 
attraction from the close juxtaposition of the two mem- 
branes, and not by the staining of the membrane itself. 
When the nucleus or head of the spermatozoon is small 
from any cause the sex-membrane covers the greater 
part of it and hence the membrane extends farther 
forward, so that when the spermatozoon makes an 
entrance through the vitelline membrane of the ovum, THE SPERMATOZOON. 
87 
the nucleus is hugged tightly by this very elastic vitelline 
membrane, which clashes with the sex-membrane and 
strips it off, leaving it outside. Now in the production of 
a male, the sex-membrane is posterior to the largest part 
The dotted line indicates the course taken by the sex-membrane, body, and tail, 
which had been detached from its nucleus, z, Part of the spermatozoon last seen; 
m, mucous clots; s, spermatozoa. 
Fig. 22.-Microscopic Field of Human Spermatozoa. 
of the nucleus or head, and when the nucleus passes 
through the vitelline membrane into the protoplasm of 
the ovum, the sex-membrane is not touched or impinged 
upon by the vitelline membrane, in which case the head, 88 
THE CELLULAR DETERMINATION OF SEX. 
body, tail, and end-piece all go in and become embedded 
in the cytoplasm of the ovum. The tail is quickly 
absorbed by the cytoplasm, while the nucleus and prob- 
ably the middle-piece persist as distinct structures or 
until maturation of the ovum shall have been completed, 
then they are absorbed and become attracted to and 
form part of the aster and nucleus of the zygote. 
I first saw the sex-membrane in a field of human 
spermatozoa, where ten or fifteen had congregated and 
were moving very actively, a little below and to the left 
of the centre of the field (Fig. 22). While my sight was 
fixed on a group a little to the right and above the centre 
of the field, I saw moving from the lower congregation 
one without a nucleus, its sex-membrane being folded 
back on the body (Fig. 23). In trying to follow it with 
the focus of the glass, it was forced from the field and I 
could not find it again. In this case, the nucleus had 
been torn from the sex-membrane and the body, probably 
by a blow from another spermatozoon or by contact 
with some hard substance. I did not see the nucleus 
after its detachment from the sex-membrane. After 
making many examinations I again saw in an open field 
a specimen in which the nucleus had been torn from the 
sex-membrane; and the nucleus was lying about one 
and a half times the length of a spermatozoon from the 
membrane (Fig. 19, I). Again, after examining many 
slides and searching many fields, I was rewarded by 
finding a perfect specimen of the sex-membrane detached 
from the nucleus. The nucleus in this case was lying 
about the length of a spermatozoon from it (Fig. 19, II). 
The fact that the nucleus was found near the sex-mem- 
brane goes to indicate very little movement after the THE SPERMATOZOON. 
89 
separation. I find that the sex- 
membrane may be detached from 
the nucleus by tapping the cover 
glass several times with a small 
piece of metal. In some specimens 
of semen containing old, small- 
headed, female-producing sperma- 
tozoa, it may be accomplished very 
readily; while in other specimens 
containing large - headed, male- 
producing spermatozoa, it is very 
hard to obtain the desired result. 
The middle part, or body, is a 
short cylindrical or conical piece, 
lying behind the head and giving- 
attachment to the tail, from which 
it is not always distinctly marked 
oft' (Fig. 16, b), a line of demarca- 
tion being the exception. In the 
young spermatozoon which has just 
become detached from the nurse 
cell, or Sertoli cell, the body is 
long and cylindrical, with no well- 
defined line of demarcation be- 
Fig. 23.-c.f, Connecting filaments. There be- 
ing only two filaments shown in this specimen, it 
is probable that the greater part of one was broken 
off near the surface of the nucleus. The laceration 
of the nucleus (Fig. 18, b) shows one to be more 
thoroughly attached than the other two; in this 
case it might have been bent back and placed in 
contact with the sex-membrane, owing to the resist- 
ance of the medium through which it passed. 
sm, Sex-membrane, inverted; b, body; t, tail; e.p, 
end-piece. 
Fig. 23. - The Sex-Mem- 
brane of the Human Sper- 
matozoon, 90 
THE CELLULAR DETERMINATION OF SEX. 
Fig. 24.-Human Spermatozoon. (Description on opposite page.) THE SPERMATOZOON. 
91 
tween it and the tail. In a few of those which have 
been detached from the nurse cell for some time, the 
body becomes conical and the line of demarcation more 
distinct. The covering, which has been described as 
the sex-membrane, is continuous with the tail cover and 
with part of the head. 
" The middle piece either contains a formed centro- 
some, or a pair of centrosomes (end-knob), or is itself a 
metamorphosed centrosome. This is probably to be 
regarded as the fertilizing element par excellence, since 
there is reason to believe that when introduced into the 
egg it gives the stimulus to division " (Wilson). The 
presence of this powerful stimulant to cell-division and 
cell-formation in the male explains the secret of the 
larger size of the male as compared with the female, and 
also the multiplicity of the primordial cells (the sper- 
matozoa) produced and given off each day, while there 
is but one (the ovum) given off each month in the 
female. The centrosome is the most active particle 
entering into cell-formation, and it is very probable that 
each and every particle forming a part of the apparently 
insoluble body (as mentioned by Sobotta, in his specimen 
of fertilization of the ovum of a rat) ultimately becomes 
active and forms the centrosome, which brings out the pa- 
ternal characteristics. This begins to dominate after the 
male has attained the age at which the female is consid- 
ered grown, the centrosome previous to this having been 
developed from the more active centrosome in the ovum. 
The body shows the same staining reactions as the 
Fig. 24.-A characteristic shape and method assumed by some spermatozoa 
in making search for the ovum. It swings its head back and forth across the 
medium in which it is located, as indicated by the dotted line, n, Nucleus; 
s.m, sex-membrane; b, body; t, tail; e.p, end-piece. Magnified 5,000 diameters, 92 
THE CELLULAR DETERMINATION OF SEX. 
acrosome, having an especial affinity for " plasma- 
stains " (acid fuchsin, etc.). At its front end, it is in 
some mammals separated from the nucleus by a short 
clear region, the neck. Like the acrosome, the middle 
piece is in some cases derived from an " archoplasmic " 
Fig. 25. -Microscopic Field of Human Spermatozoa. 
m, A clot of semisolid mucus, through which the spermatozoon, as indicated, 
bored its way. Dotted line indicates course taken after passing through clot. 
s, Spermatozoa. 
mass, representing an attraction-sphere (Lumbricus), or 
a portion of the Nebenkern (insects), and it contains, or 
according to some authors actually arises from, the cen- THE SPERMATOZOON. 
93 
trosome (salamander, mammals, insects, etc.) (Wilson). 
The spermatozoon has the power (Figs. 24, 28), by 
bending its body, to strike a downward, upward, or side 
blow, or to strike any intermediate point. It can move 
its body most gracefully in a circle. 
Spermatozoon in a characteristic position making search for the ovum. The 
time consumed in making a circuit was about eight seconds, after which it remained 
in the centre of the field for fifteen minutes. Apparently the circuits were made in 
search for a current. 
Fig. 26.-Human Spermatozoa. 
The tail is the longest part of the spermatozoon (Fig. 
16 0. measuring about five or six times the combined 
lengths of the head and body. Its terminal portion is 94 
THE CELLULAR DETERMINATION OF SEX. 
extremely slender, and forms a distinct part of the 
spermatozoon, the end-piece (Fig. 16, e.p.). It consists 
of a fibrillated axial filament, surrounded by a cytoplas- 
mic envelope or extension of the sex-membrane. The 
Fig. 27.-A Microscopic Field of Human Spermatozoa. 
In a characteristic coiled position, making search for the ovum by swinging the 
head to and fro across the current of the medium in which they are situated. 
axial filaments are outgrowths from two or three of the 
spermatid centrosomes. The tail envelope or sex-mem- 
brane arises either from the archoplasm of the Neben- 
kern (insects), together with a small amount of unmodi- 
fied cytoplasm, or from the latter alone. The axial THE SPERMATOZOON. 
95 
filament, acting as a vertebra, imparts stiffness to the 
body and tail, and probably serves or aids in conveying 
nutriment from the nucleus to the membranes of both 
body and tail. " In all animals there is a certain amount 
Fig. 28.-A Field of Dead Female-Producing Spermatozoa. 
a, b, c, d, e, Characteristic relation assumed upon the approach of death of the 
spermatozoon, f, A female-producing spermatozoon trying to enter a fixed 
leucocyte. This struggle was made for two and a half hours, striking the leucocyte 
in the same place each time and resulting in the groove as indicated. 
of work done in the daily life, and the energy put into 
such work comes from the oxidation, or from physiologi- 
cal burning, of the protoplasm. There is, therefore, a 96 
THE CELLULAR DETERMINATION OF SEX. 
constant waste of protoplasmic material which goes off 
as work done, as heat, or as residual waste matter com- 
parable with smoke and ashes of physical combustion. 
Such waste is made good by the addition of new raw 
Fig. 29.-An Interesting Field of Human Spermatozoa. 
In this case, there seemed to be, in front of the spermatozoa in the line, an ob- 
struction which t hey tried to pass. In trying to make a passage they worked their 
way from left to right about once every three minutes. 
materials in the form of blood, which is made over into 
new protoplasm " (Calkins), in all unicellular animals 
except the spermatozoa. The movements of the body 
and tail are carried on at the expense of the nutriment THE SPERMATOZOON. 
97 
stored up in the nucleus. Owing to the minuteness of the 
parts in question it remains to be explained just how the 
nutriment is distributed to them; perhaps it is, under the 
law of osmosis, facilitated by the constant movements 
of the spermatozoon. Nature has so arranged it that the 
nutriment or food from which a spermatozoon is devel- 
oped is delivered to it in such a way that it may be taken 
up and stored in the nucleus with the minimum effort 
on the part of the spermatozoon. After its detachment 
from the nurse or Sertoli cell, it is never again so situated; 
and the probability of its taking up food after its separa- 
tion is very remote indeed. This being the case, the 
food stored up in the spermatozoon is then consumed; 
and the head, being the reservoir, is gradually drawn upon 
until it becomes slim and pointed at its free end, instead 
of large, round, and club-shaped (Figs. 16, 17). Some 
of the nurse cells are smaller than others and not so 
favorably situated as to procure and deliver food to the 
spermatozoon, in which case the nucleus of the sperma- 
tozoon is not so large and well filled as one from a large 
and more favorably situated mother cell. Again, it 
occurs that very many spermatozoa-from eight to 
sixteen or according to Kblliker twenty-are attached to 
one nurse cell (Fig. 6, 6, 7), when there will be a diminu- 
tion in the size of the heads of the spermatozoa, as it is 
not possible for one mother cell to do for sixteen to 
twenty what it could do readily for from four to eight 
(Fig. 6, 1,2). When a great number of spermatozoa are 
attached to one nurse or Sertoli cell, room becomes 
limited before each nucleus has reached its normal size 
and detachment is unavoidably produced at an early 
period in the life of the spermatozoon while it is still 98 
THE CELLULAR DETERMINATION OF SEX. 
small, owing to the limited space and quantity of nutri- 
ment that had to be divided among so many. The giant 
or large spermatozoa are produced when there are only 
from four to eight individuals attached to the nurse or 
Sertoli cell. The multiplicity of spermatozoa to a single 
nurse cell is more often met with when there is a rapid 
spermatogenesis. This is the reason the young male is 
more liable to female-production. Again, when there is 
an increase of blood-pressure in the testicle of the older 
man, it is liable to produce detachment of the sperma- 
tozoon from its mother cell before the nucleus is filled to 
its maximum capacity. The blood-pressure in the tes- 
ticle is increased by sexual desire which may arise from 
psychical or ocular impressions, from mingling with 
females, from the consumption of a large quantity of 
highly nutritious foods, more especially the nitrogenous, 
or from various drugs. 
From a sextcal point of view we may arrange the parts 
of the spermatozoon under two categories as follows: 
I. The essential struchcre which plays a direct part 
in the production of the female, the nucleus (Fig. 17, n, 
18, I, 19, I, Ilf which contains the chromatin and 
probably one or two centrosomes, is all that is forced 
through the vitelline membrane and delivered to the 
cytoplasm of the ovum for the production of a female. 
2. The essential structures which play a direct part in 
the production of a male: the nucleus, body, and tail 
(Fig. 16, n, b, t, e.pf The nucleus, with one or two small 
centrosomes which are augmented by the body and all 
of the axial filament, enters the cytoplasm of the ovum. 
As the axial filament has been developed from a periph- 
eral centrosome, there is no doubt that it is homologous THE SPERMATOZOON. 
99 
Fig. 30.-Human Spermatozoa Deformed. 
I, Frequently seen in a field of spermatozoa; II, deformity seen less frequently; 
n, nucleus; s.m, sex-membrane; b, body; t, tail; e.p, end-piece. 100 
THE CELLULAR DETERMINATION OF SEX. 
to the centrosome. To produce a perfect male specimen, 
I am of the opinion that it is necessary for the tail of 
the spermatozoon to enter into and form a part of the 
first complete cell (zygote) which ultimately goes to 
produce the animal. 
The spermatozoa with large round heads are very 
active, so active indeed that it is scarcely possible to fol- 
low them with the eye when they are under a high-power 
microscope. They live from six to eighteen hours under 
the cover glass, at a temperature of 6o° Fahr. Those 
with oval heads or with heads pointed at the free end, 
in other words those with smaller nuclei or old sperma- 
tozoa, cease to move in a few minutes after remaining 
under the cover glass. The fact that the large-headed 
spermatozoa move faster and live longer, and that the 
small-headed move more slowly and die sooner, demon- 
strates beyond a doubt that the former are the young, 
and the latter the old. In studying some of their move- 
ments in a slow or rapid current of the medium, some of 
the young and old will go down the current, while others 
will make a terrific struggle to go up current, it matters 
not how rapid the movement of the medium. When 
the cover glass is in close juxtaposition with the slide, 
the spermatozoa move about continually in search for 
an ovum by swinging the head right and left, which is 
done by bending the body and a very small part of the 
tail nearest the body. This motion is not made to assist 
in locomotion, in fact it retards it. It is made for the 
sole purpose of extending and enlarging the path of 
search for the ovum. While the above is the usual 
method, some make the search by coiling the lower 
three-fourths of their tail one and a half times (Figs. THE SPERMATOZOON. 
101 
24, 26, 27), the head and 
body, in an erect position, 
swinging to and fro across 
the current when there is 
one in the medium - a 
mode of search which re- 
quires the minimum energy 
and power. When the 
coiled spermatozoa pass 
from a lower to a higher 
stratum of the medium, 
they do so by moving in a 
spiral direction, making the 
ascent without the slight- 
est visible effort on their 
part. Some of the sperma- 
tozoa which assume the 
coiled position to make 
search for the ovum, when 
changing their field of 
search, straighten them- 
selves out and move in a 
straight line, without a 
visible movement of their 
head, body, or tail, and 
going with great rapidity 
and apparent ease. It is 
only the largest and best 
Fig. 31.-a, Acrosoine; n, nucleus; 
c, cervix; t, tail; a red blood cor- 
puscle pierced as indicated by the 
spermatozoon. 
Fig. 3i.-A Spermatozoon of a Cock 
Seen in a Specimen of Semen taken 
from a Testicle Ruptured before the 
Death of the Cock. 102 
THE CELLULAR DETERMINATION OF SEX. 
specimens that assume the coiled position in their 
search for the ovum, though both male and female 
producing spermatozoa assume this position and use this 
method. 
If the cover glass is in close juxtaposition it prevents 
the spermatozoon from assuming the coiled position. To 
make a successful search for this kind of spermatozoon 
it is necessary to insert a hair under one side of the cover 
glass. 
The giant spermatozoon is occasionally met with in 
the semen of some men. Identical twins are undoubtedly 
produced by the giant spermatozoon, or a very large 
ovum, otherwise nature could not prevent the produc- 
tion of a giant, which would be destructive to the life of 
the mother. 
The medium through which the spermatozoa pass and 
in which they remain, plays a considerable role in their 
movements, the duration of their male-producing quality, 
and the length of their life. When the semen has been 
allowed to remain in the vesiculse seminales for eight or 
ten days before ejectment-in some males all the time 
regardless of the ejectment, in others only occasionally- 
it becomes thick and tenacious, and thus retards the 
spermatozoa in their movements to just the extent of 
the viscidity of the medium; for when the semen is 
viscid from any cause, more or less of the secretion 
adheres to them, and if such a load is to be dragged along 
it sometimes requires great effort on their part to move 
at all. In some cases, when a large tenacious mass of 
mucus adheres to them, they become fixed. Inasmuch 
as the nucleus or head is the storehouse for the cell 
nutriment, it is rapidly consumed in a condition as above THE SPERMATOZOON. 
103 
Fig. 32.-Spermatozoa of a Cock Less the Nucleus. 
a, a, a, a, The sex-membrane. 104 
THE CELLULAR DETERMINATION OF SEX, 
a, b, c, Characteristic bundles of sixteen spermatozoa seen in semen when taken 
from the seminiferous tubules of the testicle. 
Fig. 33.-A Field of Spermatozoa from the Cock. THE SPERMATOZOON. 
105 
described. The same physical law is exemplified in the 
case of a wagon or automobile which on a smooth, dry 
road runs readily and easily with a minimum consump- 
tion of power; but as soon as it passes into a thick, tena- 
cious, muddy road, the wheels become clogged with mud, 
progress is retarded, and more motive power is consumed. 
A thick tenacious secretion may be encountered by the 
spermatozoa at any point, near the mother or Sertoli 
cell in the seminiferous tubules, as well as in the sper- 
matic cord, the vesiculae seminales, the vagina, uterus, 
or Fallopian tubes. 
I once observed a human spermatozoon penetrating 
a small clot of mucus of considerable density. The en- 
trance was effected by an upward-downward movement 
of the head alternating with a side-to-side swinging 
(Fig. 25), and an occasional circular movement. Thus 
the size of the opening was increased in all directions 
until the nucleus or head and about one-fourth of the 
body were covered by the mass of mucus. After that it 
remained quiet for about thirty seconds, and then re- 
sumed the movements as above described until it pierced 
the opposite side of the clot, when it continued its search 
for the ovum in another section of the field. CHAPTER V. 
THE OVUM. 
The Primitive Ovum.-The primitive ova arise from 
cells of the mesothelium (peritoneal epithelium) cover- 
ing the genital ridge of the embryo. The ridge gives rise 
to the mature ovary (Fig. I, /). On account of its func- 
tion the epithelium of the genital ridge has been called 
the germinal epithelium. Both the ova and the epithe- 
lium of the Graafian follicles originate from the germinal 
epithelium as above described. The latter forms at 
first a simple layer covering the stroma, and by its 
further development becomes thickened and multiple. 
Certain cells of the germinal epithelium become larger 
than the others, and these cells are soon carried into the 
stroma of the ovary by being included in cord-like in- 
growths of the epithelium. These cords of epithelial 
cells are Pfliiger's egg tubes (Fig. 34, A). The primitive 
ova exist in multiple in the cords, each of them becomes 
surrounded by a separate envelope of epithelial cells 
(Fig. 34, B). A little later each ovum separates from 
its neighbor and appears as a round cell with a clear 
nucleus and distinct nucleolus. They are closely invest- 
ed at first by a single layer of flattened cells smaller than 
the ovum itself. The young egg-cell, together with its 
epithelial envelope, constitutes the so-called primordial 
follicle (Fig. 34, B, C). 
Growth and Development of the Ovum.-The ovum 
enlarges until mature, when it becomes much larger 
106 THE OVUM. 
107 
Fig. 34.-Figures Showing Various Stages in the Development of the 
Graafian Follicle of the Rabbit. 
A, From ovary of young rabbit, showing "egg-tubes" of Pfliiger growing in from 
germinal epithelium; some of the tubes contain primitive ova; B, primitive 
Graafian follicle, with a single layer of follicle-epithelium; C, a young Graafian 
follicle, with a single layer of follicle-epithelium; D, a somewhat older follicle, with 
the second layer forming within the first; E, a more advanced follicle, showing two 
complete layers of columnar epithelium surrounding«the ovum within the follicle. 108 
THE CELLULAR DETERMINATION OF SEX. 
than any other cell in the body of the parent. It usually 
becomes quite spherical. The shape of the egg does not 
necessarily remain spherical, but may be altered by 
external pressure. The nucleus becomes large and 
spherical and assumes an excentric position within the 
ovum. The cellular network becomes very distinct, and 
its meshes become filled with ovoid or crystalline solid 
enclosures, which are of an albuminoid character. The 
enclosures form the part which is called the deutoplasm. 
The deutoplasm is the same as the yolk-substance 
of the earlier writers, and it is a store for nutritive 
material from which the protoplasm draws subse- 
quently to support its growth. In all vertebrates an 
ovarian envelope, the zona radiata, is formed (Fig. 
35, z). The vitelline membrane is always formed 
inside the zona radiata by the ovum before it reaches 
maturity. 
Primordial Ovum.-The ovary at birth and up to 
the climacteric period contains small egg-cells, some of 
which develop from time to time into mature ova. These 
small egg-cells together with their follicles present a 
constant appearance at all ages. These egg-cells or 
ova are the primordial ova, which lie in the stroma of 
the ovary immediately below the albuginea and never 
in the medullary region. They are slightly irregular 
globules, the diameter of which is about one-third that 
of the mature ova. The protoplasm is finely and evenly 
granular and consists of a uniformly clear matrix and a 
very fine reticulum. Yolk granules have been found in 
the primordial ova of birds and various mammals; but 
this is not the case in man. The protoplasm is naked- 
there is no special cell membrane. The nucleus is round THE OVUM. 
109 
and bounded by a very distinct membrane and lies in 
the centre of the cell; it contains a round excentrically 
placed nucleolus. There is a loose network of fibres in 
the nucleus, which is different from that of the nucleo- 
lus, as is shown by its different staining. Each primor- 
dial ovum is surrounded by a very thin epithelial en- 
velope, with scattered fusiform nuclei. 
Growth of the Ovum and Primary Follicle.-The 
follicles remain for a long time without change, but 
from time to time certain ones of them develop. In a 
mature ovary we can always find several stages. The 
cause of the development of the follicles is unknown. 
The primary follicles are always near the surface, but as 
they grow in size they move deeper into the stroma 
(Fig. 12). The first step is the multiplication of the cells 
of the follicle (Fig. 34, B, C, D) which converts the 
follicle into a layer of cubical cells with the nuclei at an 
even height. During this change in the follicle the 
primordial ovum does not alter in size. 
The second step is the elongation of the cells into a 
cubical form, with an accompanying enlargement of the 
ovum. The growth of the ovum affects the protoplasm, 
the nucleus, and the nucleolus, all of which increase their 
dimensions. The follicular wall steadily increases in 
thickness. At first it remains single-layered, but the 
nuclei take their places at various levels, and a little later 
it becomes several-layered, and then the formation of the 
first envelope (zona pellucida) around the ovum begins. 
During the growth of the follicle there is a network of 
blood-vessels formed around it. The layer of blood- 
vessels constitutes the tunica vasculosa or theca folliculi. 
The first vessel is a single loop which embraces the 110 
THE CELLULAR DETERMINATION OF SEX. 
follicle; other loops approach and unite with their 
fellows to form a network. 
After the epithelium of the primary follicle has de- 
veloped into many layers, there appear in it rounded 
vacuolated spaces which increase in size and finally 
become confluent, so that there is a fissure formed in the 
epithelium. This fissure divides the epithelium into 
two layers, an inner one immediately surrounding the 
ovum, and an outer one next the stroma of ths ovary. 
Since the fissure is incomplete around the follicle there 
is one place where the two layers are united (Fig. 12, f). 
The place of union, though variable in position, is always 
on the side of the follicle away from the surface of the 
ovary. This fissure is filled with serous fluid known as 
liquor folliculi. The appearance of the fissure changes 
the primary into a Graafian follicle. 
The Graafian follicle is bounded by a layer of epithe- 
lium known as the membrana granulosa. To a part of 
its walls on the side away from the surface of the ovary 
is attached a mass of cells more or less globular in shape. 
This mass is known as the discus or cumulus proligerus. 
It encloses the ovum. 
The Ovum.-The ovum or female gamete is a large 
cell, in fact the largest in the body, in most cases visible 
to the naked eye even in the ovary (Fig. 35), while the 
spermatozoon or male gamete is invisible and the small- 
est nucleated cell produced in the body. The female 
gamete or ovum is a non-motile, passive cell, which is 
wholly dependent upon the ciliated epithelium of the Fal- 
lopian tube to be picked up and wafted into the uterus for 
further development, while the spermatozoon possesses 
the power of active movement, and by its inherent power THE OVUM 
111 
makes its way from the mother cell (cell of Sertoli) in 
the seminiferous tubule to the vesiculae seminales, a 
distance of thirty or forty feet. From the vagina after 
insemination it swims out of the masculine seminal 
Fig. 35.-Human Ovum; Highly Magnified. 
z, The zona pellucida, showing the faint striae and a few cells of the discus pro- 
ligerus, which are adherent to it; v.m, vitelline membrane; c, centrosomes; n, 
nucleus; u.s, nucleolus; d.c, cells of the discus proligerus. 
medium into the maternal secretions to the upper part 
of the Fallopian tube, where it meets the ovum and 
makes its way through the membranes into its cytoplasm. 
The ova are usually spherical in shape, which renders 
their transportation by the cilia from the ovary to the 112 
THE CELLULAR DETERMINATION OF SEX. 
cavity of the uterus more sure and easy. Each ovum 
contains a large nucleus, a centrosome, and a large 
quantity of protoplasm, and is enclosed in a stout very 
elastic membrane, which may, or may not, have a special 
aperture known as the micropile. 
The Micropile.-When the ovum is surrounded by a 
protective envelope before fertilization it is usually 
perforated by one or more openings known as micropiles, 
through which the spermatozoon makes its entrance. 
Where there is but one micropile it is more often situated 
near the upper or anterior pole (fish, and many insects), 
but it may be situated at the opposite pole (mollusks 
and some insects). In some insects it is situated on the 
side. In the eggs of many insects there is a group of 
half a dozen or more micropiles near the upper pole of 
the egg, in which case more than one spermatozoon may 
enter the egg, though only one is concerned with the 
process of fertilization. The micropile has not been 
isolated in the enveloping membrane of the mammalian 
ovules, and its presence in them is very doubtful. 
Membranes.-The coverings of the ovum may be 
arranged in four groups. They are: 
(i) The vitelline membrane, which is formed by the 
ovum itself. 
(2) The zona radiata, which is formed outside the 
ovum by the secretion of the follicle-cells. 
(3) Accessory envelopes, secreted by the walls of the 
oviduct. 
(4) Coverings secreted by the accessory glands. 
(1) The Vitelline Membrane (Fig. 35, v.m.).-The vi- 
telline membrane is a very thin, clear, tough, and elastic 
membrane immediately investing the yolk, being separat- THE OVUM. 
113 
ed from the zona by a narrow space, and is a product of 
the ovum itself. It is formed a short time before the 
ovum matures, and is most distinct at the time of the 
formation of the polar bodies. The presence of this 
membrane is doubted by many writers, but its existence 
has been demonstrated. The entrance of the sperma- 
tozoon into the cytoplasm after it reaches the ovum is 
accomplished only after a prolonged hard struggle on 
its part. That there is a very stout elastic membrane 
enveloping the ovum may be demonstrated by placing 
an ovum upon a slide and covering it with a cover glass, 
by making a little pressure it can be compressed until it 
is comparatively flat, and immediately upon releasing 
the pressure it will resume its characteristic shape 
(spherical). Piersol speaks of this membrane and says, 
"The liberated ovum is surrounded by a protecting 
membrane, the zona pellucida, which sometimes exhibits 
a faint radial striation. This envelope must not be 
confounded with the vitelline membrane, since it is not 
strictly a part of the ovum, but a product of the sur- 
rounding epithelial cells lining the little sac, the Graafian 
follicle, enclosing the egg while within the ovary.'' 
Minot says, " Considerable doubt in regard to the 
presence of this membrane in vertebrates, and especially 
in mammals, has been expressed by various writers, 
but its existence seems to me to have been sufficiently 
demonstrated.'' 
It is this tough elastic vitelline membrane with which 
the sex-membrane of the spermatozoon clashes in case 
of female-production. The tougher this membrane the 
greater the probability for female-production, for these 
reasons: (i) The continued struggle reduces the size 114 
THE CELLULAR DETERMINATION OF SEX. 
of the nucleus. (2) When the spermatozoon passes, 
slowly through this membrane into the cytoplasm the 
chance is increased that the sex-membrane will be 
stripped off the nucleus. (3) The hugging of the nucleus 
more tightly by a more elastic membrane on its entrance 
into the cytoplasm would increase the chance that the 
sex-membrane will be stripped off. 
(2) The Zona Radiata (Fig. 35, 2).-The zona 
radiata is a transparent membrane, varying in thickness, 
which appears as a clear bright ring under the microscope. 
This membrane is pierced by very faint, clear, radiating 
pores, which produce the appearance to which the term 
zona radiata refers. The faint striations are probably 
due to the passage of the more thin, clear nutriment from the 
cells of the discus proligerus through the zona radiata to the 
ovum. The faint striations are produced by the difference in 
color or in the refractive power of the old viscid secretion, the 
latter of which has been received immediately from each cell 
of the discus proligerus. It is probable that both the ova 
and the cells immediately investing it, contribute to the 
formation of the zona pellucida, and that it is formed from 
the waste products. All writers agree that the spermatozoa 
can enter the zona radiata and swim around in it with 
apparent ease and freedom. This fact in itself makes it 
evident that this is not a tough or an elastic membrane. 
Any one who has ever studied the physical power of a 
spermatozoon knows that it cannot swim around in the 
stroma of a tough elastic membrane. This membrane, 
through which the spermatozoa move and swim freely, 
serves as a protection to them while making entrance into 
the cytoplasm of the ovum, by preventing them from 
being wafted away from the ovum in its progress through THE OVUM. 
115 
the Fallopian tube. It has been frequently stated that 
a few of the cells from the discus proligerus remain 
attached to the ovum on its extrusion from the Graafian 
follicle. The extrusion of an ovum from its follicle has 
never been witnessed under normal conditions, and it is 
improbable that the cells remain intact in the fully 
developed ovum. The premature removal of the ovum 
from its follicle would, however, augment the chance 
for some of the cells from the discus proligerus to remain 
in contact with it. 
The ova of mammals receive the deposit of the 
follicular secretion only as above mentioned. There 
are some eggs that are naked and remain so throughout 
their development (certain of the coelenterates), while 
there are others that develop the vitelline membrane 
almost instantaneously upon fertilization (the entrance 
of the spermatozoon), of which the sea-urchin is a type. 
(3) The envelopes secreted by the oviduct, which may 
form a coating of nutritive material, or a protective 
shell, or both, as in the hen's egg, of which the nutritive 
white is secreted by the upper part, and the calcareous 
shell by the middle part of the oviduct. 
In the bird and reptile families, the ova are fertilized 
before they leave the Graafian follicle. The eggs are ferti- 
lized very soon after insemination in both of these families. 
That the spermatozoa of birds are capable not only of 
penetrating a membrane, but of piercing both walls of a 
cell, is shown in Fig. 31, where the red blood cell is pierced 
by the spermatozoon, which fact establishes their ability 
to pierce a membrane beyond question. 
(4) Covering Secreted by Accessory Glands.-This 
is seen in the slime in which the eggs of snails are em- 116 
THE CELLULAR DETERMINATION OF SEX. 
bedded, or in the tough capsules in which leeches lay 
their eggs. 
The Cytoplasm.-The cytoplasm is the substance of 
the cell-body, which may be termed the ooplasm, and 
which is frequently spoken of as yolk, but does not in- 
clude the nucleus, although the nucleus is situated within 
its stroma. The cytoplasm is composed of protoplasm, 
which forms a reticular structure, with the yolk-granules 
lying in its interstices. The granules in the centre of 
the ovum are matured first, which is shown by the 
granules growing less in size from the centre to the 
periphery, where they are ultimately lost. It is probable 
that the specific gravity of the granules is greater than 
that of the nucleus, and this is why it moves or migrates 
to the outer zone of the cytoplasm as the granules are 
advanced to maturity, or it may be that the taking of 
food by the nucleus from the peripheral border produces 
a current in which the reticular meshwork cannot form, 
and as the granules are formed from the centre the 
nucleus is gradually pushed by their formation to the 
peripheral zone, where it is usually found in the mature 
ovum. 
The cytoplasm serves as a field in which nuclear divi- 
sion may take place. Segmentation cannot take place 
in a cell consisting only of a nucleus and centrosome, 
unless surrounded by a protoplasmic field. The sperma- 
tozoa are cells consisting only of the nucleus and a 
metamorphosed centrosome. 
The Nucleus (Fig. 35, n).-The nucleus or germinal 
vesicle always lies in the protoplasmic zone, just outside 
of the granular mass. As the granular mass or deuto- 
plasm extends, the nucleus is pushed toward the peri- THE OVUM. 
117 
phery. Its form is spherical, surrounded by a distinct 
membrane; but during the growth of the egg it may 
become irregular or even amoeboid. Its migration 
through the cytoplasm toward the source of food has 
been shown, in the case of insect eggs, by Korschelt. 
" The nucleus is generally regarded as the controlling 
centre of cell-activity, and is the primary factor in 
growth, development, and the transmission of specific 
qualities from cell to cell and so from one generation 
to another " (Wilson). The experiments of Seeliger, 
Morgan, and Drisch prove that fertilization of an entire 
enucleated ovum of one species by a spermatozoon of 
the other shows a very considerable range of variation; 
and while it was at first thought that the animals so 
produced would exhibit purely paternal characters, 
further experimenting by Seeliger ('94), Morgan ('95, 4), 
and Drisch ('98, 3) showed that this result was not 
entirely conclusive, since hybrid larvae arising by the 
fertilization of an entire ovum of one species by a 
spermatozoon of the other present a very considerable 
range of variation; and while most such hybrids are 
intermediate in character between the two species, some 
individual may nearly approximate to the characters 
of the father or the mother (from Wilson). Here it is 
that the centrosome which is still in the cytoplasm of the 
ovum advances to activity in the cell division, thus main- 
taining and developing the maternal characteristics. 
a. The nuclear membrane is a well-defined delicate 
wall surrounding the nucleus. 
b. The nuclear reticulum forms an irregular branching 
network, consisting of two different constituents. The 
first of these, forming the general protoplasmic basis of 118 
THE CELLULAR DETERMINATION OF SEX. 
the nucleus, is known as linin. The second constituent, 
a deeply staining substance, is known as chromatin 
(Flemming). The chromatin is one of the essential 
structures in segmentation of the cell. It is not the 
active part of the cell, but the most essential part of 
the cell to be acted upon. The fact that the polar 
bodies are formed apparently for the sole purpose of 
eliminating all the superfluous chromatin, is indicative 
of its being a burden rather than an assistant to cell- 
division. A great or an excessive quantity of chromatin 
in the active formation of the nucleus will not hasten 
but slow down cell-division. The chromatin or chromo- 
somes of a cell, while absolutely necessary for cell- 
division, is to be regarded as the burden, and not as the 
dynamic centre of cell-division. 
The Nucleoli.-There are at least two different kinds 
of nucleoli. The first and most important is the true 
nucleolus or plasmosome, which is spherical in shape, 
is enclosed in a very delicate membrane, and is shown 
by staining to differ from chromatin. It is probable 
that this nucleolus serves in receiving and distributing 
nutriment to the various parts of the nucleus, in which 
case it should be situated in the nucleus next to the 
peripheral zone, or on the side from which the greatest 
part of the nutriment is received. The nucleoli of the 
second kind are different from those of the first in that 
they are not surrounded by an enveloping membrane, 
are more often irregular than spherical in shape, and 
agree in staining reaction with chromatin, and there is 
good reason to believe that they are merely small masses 
of chromatin in the resting state. 
The Centrosome (Fig. 35, c).-The centrosome is a THE OVUM. 
119 
minute particle, and is usually present in pairs. In 
the ovum they are always in the cytoplasm, lying 
near the nucleus or in an indentation in it. Van 
Beneden, Boveri, and many late writers regard the 
centrosome as a distinct and persistent cell-organ, which 
like the nucleus was handed on by division from one 
cell-generation to another. My discovery not only 
proves that it is a distinct and persistent cell-organ, 
but that through it the sex of all animals is controlled, 
and that the characteristics are either transmitted by it, 
or developed through the power of its presence. When 
only the nucleus and a very small centrosome are de- 
livered to the cytoplasm of the ovum by the spermato- 
zoon, a female is produced. In this case the aster is 
formed from the resting aster situated in the cytoplasm 
of the ovum. The chromatin of mammals, birds, fish, 
and reptiles entering into the production of females is 
identical in quantity with that of the male. A more 
powerful centrosome is necessary to produce the male 
in the above group of animals. This is furnished to the 
ovum by the body and the tail of the spermatozoon 
entering the cytoplasm of the cell. The large centro- 
some, or the material from which the masculine part 
of the aster is formed, is stored in the body and the 
tail of the spermatozoon. In Heterokis, Lygacus, and 
Euschistus, and the entire series of this species, the 
size and quality of the centrosome, or that part of the 
cell from which the aster is produced, are the same 
in power in both the male and the female. The dif- 
ference in the zygote of the sea animals consists simply 
in the greater number of chromosomes in the female 
and at least one less in the male. The effect of this is 120 
THE CELLULAR DETERMINATION OF SEX. 
precisely the same as the addition of just a little larger 
centrosome to a given quantity of chromatin for the 
production of a male, and a little less for female-produc- 
tion. In the honey-bee, all the eggs without exception 
form two polar bodies, and the unfertilized egg invariably 
Fig. 36.-Diagram Showing the Reduction of the Chromosomes during the 
Maturation of the Ovum. 
p.o, Primary oocyte or ovarian egg; s.o, secondary oocyte; p, first polar body; 
o, mature ovum; s.p, secondary polar bodies. 
develops into a male. In this case the burden (one-half 
of the number of chromosomes) has been eliminated. 
Yet the ovum still contains the same quantity of centro- 
some (or aster) forming substance. The centrosome 
acting upon a small number of chromosomes gives rise THE OVUM. 
121 
to a more rapid cell-division, which produces the drone 
or male bee. If the queen bee has copulated and the 
ovum is fertilized, only the nucleus containing the 
chromosomes is added. The tail of the spermatozoon 
(the centrosome-forming substance) is left without, 
with the result of inevitable female-production. 
Maturation of the Ovum.-" The term maturation is 
restricted by usage to the series of phenomena accom- 
panying the expulsion of the polar globules which occurs 
Polar bodies. 
Spermatids. 
Fig. 37.-Diagram Showing the Similarity of the Maturation Phenomena 
to those of Spermatogenesis. 
i, p.o. Primary oocyte or ovarian egg; s.o, secondary oocyte; p, first polar 
body; o, mature ovum; s.p, secondary polar bodies. 2, s, spermatocyte of the 
first order; d.s, the daughter spermatocytes; sp, spermatids. 
after the cell has attained its full size, and just before 
or just after the separation of the ovum from the ovary " 
(Minot). I am of the opinion that maturation takes 
place upon relief of the pressure to which the ovum is 
subjected in the Graafian follicle, which may occur 
before its expulsion owing to the thinning of the tunica THE CELLULAR DETERMINATION OF SEX. 
122 
albuginea with the consequent relief of pressure. A 
polar globule is a small, nucleated mass, consisting 
chiefly of chromatin and almost destitute of cytoplasm, 
extruded from a fully grown egg-cell. When an ovum 
is about to mature the nucleus moves to the surface, and 
contraction of the vitelline membrane occurs. The 
contraction of the vitellus is probably a constant phe- 
nomenon and it is effected by the expulsion of fluid 
from the protoplasm, so that a clear space separates the 
zona radiata and vitellus. After the formation of the 
second polar globule, the chromatin has been reduced 
to one-fourth of that which entered into the formation 
of the first polar spindle. In the formation of the 
second globule, the chromosomes are always reduced to 
one-half the number characteristic of the species to 
which the animal belongs. CHAPTER VI. 
MENSTRUATION. 
Synonyms.-Menses; menstrual flow; menstrual flux; 
flow; catamenia. Women have various popular names 
for it, mostly metaphorical and conventional. These 
terms are used in reference to that phenomenon in the 
human species while the following terms are applied to 
the homologous condition in animals: Heat; rut; must; 
oestrum, etc. 
By the term menstruation is meant the monthly 
hemorrhage which takes place in the uterus during the 
child-bearing period of the normal woman, except during 
pregnancy and lactation, when it is usually suspended. 
Menstruation is the only guide to the control of sex and 
for that reason each and every phase of the phenomenon 
should be thoroughly understood. 
Puberty.-The first occurrence of menstruation with 
the concomitant changes marks the epoch of sexual 
maturity at which, in the female, impregnation becomes 
possible. The signs (as Parvin gives them) are: " The 
girl's pelvis enlarges and her breasts notably increase in 
size as she enters this period of life; the one change 
indicates preparation for childbirth, the other provision 
for the nourishment of the newborn. The external 
genitals are developed, and hair grows upon the mons 
veneris and upon the labia majora; the circumference 
of the neck is greater, and the voice changes; the body 
123 124 
THE CELLULAR DETERMINATION OF SEX. 
is fuller and more gracefully rounded; sharp, irregular, 
and angular outlines are replaced by symmetrical curves, 
and new beauty of form and of general expression is 
manifested-it is the springtime of female life, the bud 
unfolding into the flower. The girl passing into woman- 
hood puts away childish things, turning from frivolous 
amusements, from toys and plays, or from rude sports 
in which she has found pleasure; she enters a new life, 
has new thoughts, desires, and emotions. Hitherto she 
has been living solely in and for the present; but now the 
future with its lights and shadows, its hopes and fears, 
makes a large part of her life. She is more sensitive and 
reserved, and manifests a modest dignity, giving and 
expecting respect; her individuality becomes more 
manifest, her sense of duty stronger, and her ambition 
greater." 
This remarkable transformation is the expression of 
important changes in the internal generative organs, 
especially in the ovaries, for if the latter be absent or 
undeveloped, the distinctive sexual characteristics fail. 
During infancy and childhood the ovaries slumbered 
while nature's forces were busy building up the individ- 
ual, and it is only when this end has been in good degree 
attained that provision is made for the continuance of 
the race. The ovaries now awaken from their silent, 
inactive state, notably increase in size, and enter upon 
the discharge of their special function; they determine 
the sexual character, and for thirty years or more exer- 
cise a dominant influence upon the female organism. 
Though commonly designated as uterine appendages, in a 
true physiology the uterus ought to be regarded as their 
appendage. The functions of the ovaries are the matur- MENSTRUATION. 
125 
ing of the ovum and the maturing and rupture of ovisacs, 
with the consequent escape of ovules which arc thus 
offered for impregnation, which process is known as ovu- 
lation, and as it occurs independently of sexual congress, 
it is called spontaneous ovulation. The menstrual func- 
tion is not generally established at once, but for the 
first few months there may be only premonitory symp- 
toms of a vague and uncomfortable nature when there 
occurs a slight discharge of mucus, later a discharge of 
mucus slightly tinged with blood, and still later the 
regular menses are established. 
Menstruation is usually established at about the time 
of puberty, and while in some childbearing women it 
is absent through life, in others it is absent until after 
pregnancy. This epoch is ushered in by the entrance 
of the ovary into active function. The universal law 
of periodicity now acts upon conditions prepared to 
respond. The determining conditions are-I. The energy 
of the sexual sense; 2. Latitude and mean temperature 
of the habitation; 3. Occupation and diet; 4. Race. 
1. Sexual Energy.-In some individuals the tendency 
to early sexual maturity is well marked. The ovaries 
assume their function at a very early date; hair grows 
early; the system generally exhibits evidence of precoci- 
ty; and the sexual proclivities are manifested. Susewind 
saw a child 27 months old, who had menstruated from 
the age of 12 months; she exhibited the molimen hemor- 
rhagicum; her breasts and mons veneris were developed 
as in girls of 14 or 15. The following, reported by Mr. 
Dodd from Barnes' " Obstetrics," is therefore of special 
interest. On August 8, 1871, Mr. Dodd delivered F. M. 
of a female child. This child began to menstruate at 126 
THE CELLULAR DETERMINATION OF SEX. 
12 months, not very regularly at first, but varying from 
four to six weeks' intervals. The last two years (1878 
79, 1880) the menstruation was every three weeks. The 
last appearance was on June 22, 1880, when she became 
pregnant. Mr. Dodd attended her in her labor on March 
17, 1881. The child weighed 7 lbs. It died some time 
after in convulsions. The labor was not difficult. The 
hirsute growth on pubes and in axillae was profuse; the 
breasts a week after labor were large and gorged with 
milk. The child was thus pregnant before she was 9 years 
old. This duration of her gestation may be estimated 
at 269 days. Ahlfeld reports the case of Anna Mummen- 
thalen who menstruated from her second to her fifty- 
second year. In her eighth year she became pregnant, 
and gave birth to a child in her ninth year. Montanaier 
cites the case of a child less than six months old, very 
large and with well-developed breasts. D'Outrepont 
reports a birth in the ninth year of age without the es- 
tablishment of menstruation. 
In support of the fact that pregnancy can take place 
in complete absence of menstruation, Ahlfeld reports 
the case of a woman who had never menstruated, but 
who bore a child in her thirty-second year. He also 
reports the case of a woman who had had eight children, 
but who had never menstruated. Parvin reports a 
case in which menstruation began at the age of three 
years and a half, and continued regularly. Ploss has 
collected forty-five instances of precocious menstruation, 
the oldest of the subjects being in her eighth year. 
But in some of these girls there was disease of the 
ovaries, in others hydrocephalus, and in still others 
rickets; nevertheless, the majority of the children were MENSTRUATION. 
127 
healthy. In some instances of precocious menstruation 
precocious maternity was observed. Robert Barnes 
reports several cases of premature menstruation in which 
exhaustion and death occurred, but this was not the 
rule. Kussmaul says precocious menstruation is some- 
times the result of disease, especially of new growths 
in the ovary. Cases in which births occurred after the 
cessation of menstruation are also noted. Kennedy 
cites the case of a woman sixty-two years of age who gave 
birth to a child. This patient had, in all, borne twenty- 
two children. Menstruation had always been regular- 
La Mott reported a case in which a woman gave birth 
to a child seven years after the menopause. The 
time of cessation normally occurs about the forty-fifth 
year. The above cases are the most abnormal on record 
which have occurred in both England and the United 
States during the past century. Precocity in the human 
female attended by menstruation is undoubtedly due 
to an excessive quantity of blood supply to the ovaries. 
Should such a condition present itself in those under 
seven years I would unhesitatingly advise the ligation of 
the larger artery (the ovarian, or the ovarian branch of 
the uterine arteries), for the reason that modern surgery 
has advanced to such a degree that the danger attend- 
ing such an operation could not be compared to the 
abominable condition from which the child must other- 
wise suffer. Amenorrhoea is present in such a small 
number of women that it is scarcely necessary to con- 
sider them. Menstruation is usually established after the 
first pregnancy, when the women can produce the desired 
sex. In the two cases of amenorrhoea among the records 
of one thousand families which I shall introduce later, 128 
THE CELLULAR DETERMINATION OF SEX. 
pregnancy followed immediately in each case, a boy 
and a girl having been born promptly nine months after 
marriage. While the sexes differ in these cases, this 
condition favors an excess of females. While pregnancy 
immediately followed insemination in both of these 
cases, such result is very unusual. Parvin gives the 
following: " Apathy of the genital sense is mani- 
fested by delayed menstruation in persons whose health 
is good. This delay may extend to four or five years, 
or even a longer time, beyond the period when men- 
struation usually begins; in some cases menstruation 
did not occur until after one or more pregnancies, but 
of course the probability of conception prior to the es- 
tablishment of this function is very small." According 
to Villaret, Joan of Arc was " exempt from the tribute 
which women pay the moon "; and he suggests that 
this exemption was due to her high destiny. She was 
only twenty years old when she was executed, so that, 
admitting the fact of her amenorrhcea, it is possible 
that the establishment of her menstruation was simply 
delayed. 
2. Latitude and mean Temperature of the Habitation. 
-Barnes quotes the following: " Joulin divides the peo- 
ples subjected to his statistical analysis into three zones. 
The temperate zone, situated between lat. 33° and 54° 
north; the second, belonging to hot climates, between 
33° and the equator; the third corresponds to the cold 
regions, and extends from lat. 54° to the pole. Men- 
struation sets in in the temperate latitudes toward the 
fifteenth year; in the hot regions about the twelfth year; 
and in the cold about the fifteenth or sixteenth; but 
great variations occur in each region, some of which are MENSTRUATION. 
129 
explained by the other influences specified." And farther 
on he says that, generally speaking, heat promotes men- 
struation, cold retards it, and refers to some women who 
menstruate regularly, perhaps profusely, in India, and 
see scarcely anything in England. Others in England 
menstruate only in the summer. Edgar gives the follow- 
ing: "It is said that English girls in Calcutta menstruate 
no earlier than in England, although subjected to the 
same climatic influences as the Hindoos, one or two per 
cent of whom menstruate as early as the ninth year, while 
twenty-five per cent menstruate at twelve years of age. 
The children of the superior classes, being of a higher 
nervous organization, are apt to menstruate earlier. 
Their manner of life is more luxurious and mental 
stimulation is premature, as shown in the earlier period 
of menstruation. As to the influence of climate, it has 
no doubt been exaggerated, although the general rule 
holds that menstruation occurs somewhat earlier in the 
tropical than in the Arctic regions." Parvin says: 
" In temperate climates girls usually begin to menstruate 
when from thirteen to fourteen years old; in warm 
climates the function occurs earlier, in cold later." 
Raciborski states that a year's difference in puberty 
corresponds to a difference of eight or nine, sometimes of 
only four, degrees of latitude. His tables, including 
25,952 observations, show that there is a difference of 
three years ten months and thirteen days between the 
time of the first menstruation of the girls living in Cen- 
tral Asia and that of those living in Lapland. Krieger 
gives as the two extremes, eighteen years in Swedish 
Lapland, and ten years each in Egypt and in Sierra 
Leone. 130 
THE CELLULAR DETERMINATION OF SEX. 
The fad that the girls from a temperate climate subjected 
to the heat of a tropical climate do not menstruate any earlier, 
and those from a hot tropical climate subjected to the cool 
temperate climate do not menstruate any later, is good proof 
that menstniation is not hastened by heat or delayed by cold; 
but that the variation of the first menstruation is due to the 
universal law which is found throtighout the animal king- 
dom. Men or animals of short life are early to mate and 
propagate, while those of long life are late to mate and propa- 
gate. 
As a general rule, it will be found that the longevity 
of those living in a hot climate is from four to six years 
shorter than that of those living in a cold or temperate 
climate. The age at which menstruation begins depends 
upon the primordial vitality of the girl and not the tempera- 
ture to which her body is subjected. 
3. Occupation and Diet.-The easier classes, who live 
luxuriously, usually menstruate early and freely, while 
those who live hard laborious lives menstruate less and 
later. Girls changing from country life and habits to 
those of a city, to work in sedentary occupations, 
housed in hot rooms, and subject to the promiscuous 
mixing of sexes, may menstruate sooner (Barnes, who 
refers to Stoltz, Brierre de Boismont, Leudet, Bernard, 
Faye, Mayer; Edgar, who refers to Clay, " Brit. Record 
of Obstet. Med.," vol. i., and Parvin). 
4. Race.-The time of the first menstruation, as to 
age, varies in different races. Races of long life that 
are late in reaching puberty will begin to menstruate 
later than those of short life and early maturity or 
puberty. Otherwise the onset is the result of direct 
stimulation of the sexual organs by an increased flow of MENSTRUATION. 
131 
blood to them, which may be superinduced by psychical 
or ocular impressions, or by congenitally large arteries 
to these organs. The Jewish race, which so strikingly 
maintains its individuality in all ages and places, and 
among all peoples, shows in regard to the first occurrence 
of menstruation but little differences of time, no matter 
what differences of latitude or climates are compared 
(Parvin, Barnes, etc.). The daughters of English 
residents in India do not menstruate as early as the 
native Hindoo girls (Parvin, Barnes). Parvin refers to 
the report given by Depaul: " Negresses born under 
the burning sky of Africa or of South America menstruate 
early, and those in Europe are equally precocious." A 
mother who menstruates early or late is liable to transmit 
this peculiarity to her daughters, independent of race 
(Parvin). 
The phenomena constituting and attending menstrua- 
tion are constitutional and local. 
(i) The constitutional phenomena consist of pain in 
various parts of the body, hot flashes, chilliness, and 
hysterical symptoms. There are often considerable 
changes in the nutritive processes and the excretion of 
urea by the kidneys is lessened, dark circles appear 
under the eyes, the breasts swell and become painful. 
The reflex nervous system is usually at its maximum 
point of irritability and there is often depression with 
drowsiness, a sense of fulness and oppression is felt in 
the head and a feeling of general discomfort, weariness, 
and a marked distaste for active exercise. 
(2) The local phenomena are those of hyperaemia and 
then congestion of the female sexual organs. The 
ovaries, uterus, Fallopian tubes, broad ligaments, vagina, 132 
THE CELLULAR DETERMINATION OF SEX. 
vulva, and mammary glands, all participate more or less 
in the hyperaemic condition which passes into congestion 
and sometimes inflammation of the parts. The ovaries 
first become congested, then the uterus becomes much 
congested, the cervix softens and is of a bluish color, 
with relaxation of the external and the internal os. The 
uterine mucous membrane is also swollen, congested, 
and raised into folds which give the surface an irregular 
appearance; abundant secretion pours from the glands, 
and, at least in some cases, the epithelium desquamates, 
and the capillaries losing their support, their walls un- 
dergo fatty degeneration, burst, and discharge the blood. 
The tubes are also congested and thickened, and blood 
sometimes escapes into them. The vagina becomes 
darker in color, glandular secretion is abundant, and the 
temperature is slightly elevated, often by i° F. The 
whole vulva is swollen and tense, and pruritus may 
occur. The following is an excellent observation made 
by George Harley, as given by Barnes: " A married 
woman, set. 23, drowned herself when menstruation 
was impending. The uterus was congested and enlarged 
to about one-half more than its usual size. On section 
the uterine tissue was rosy, and the open mouths of 
its blood-vessels were distinctly visible. The vagina was 
somewhat congested externally, but of the normal color 
internally. The mouth of the womb was filled with a 
white tenacious mucus, while the mucous membrane 
of the interior was hypertrophied throughout its whole 
extent, of a pink color, which gradually increased in 
depth toward the fundus, at which it attained a dark 
livid color, and was covered with a quantity of blood. 
The blood was in greatest quantity at the mouths of the MENSTRUATION. 
133 
Fallopian tubes, but neither the congested nor the hem- 
orrhagic state of the mucous membrane extended be- 
yond the openings of the tubes. Their interior was 
quite white and clean at the uterine extremity, but 
highly congested and filled with a milky fluid toward 
the fimbriated end. This mucous secretion was loaded 
with ciliated and other epithelium. The ovaries were 
enlarged, especially the left one, which contained a 
Graafian vesicle, 0.75 mm. in diameter, ready to burst, 
and which actually burst while being handled. The 
vesicle contained a clear straw-colored serum, with a few 
flakes of the membrana granulosa floating in it. On the 
interior of the vesicle were numerous vessels, which 
gave to it a highly congested appearance." 
Howell gives the following: " Menstruation is a 
phenomenon of the uterus. The lining mucous mem- 
brane, the endometrium, in the period of four or five 
days preceding the flow, becomes rapidly thicker and 
its superficial layers are congested with blood, and indeed 
in places small collections of blood may be noticed. 
Opinions differ very much as to the change undergone 
by this thickened membrane during the flow. According 
to some authors, most of the membrane is thrown off 
and the blood escapes from the denuded surface mixed 
with pieces of the membrane. According to others, no 
material destruction of the membrane occurs, the blood 
that escapes being due to small capillary extravasations 
or perhaps mainly to a process of diapedesis. It would 
seem that the amount of destruction of the endometrium 
must be subject to individual variations. After the 
cessation of the flow the mucous membrane is rapidly 
repaired by regenerative changes in the tissue; the 134 
THE CELLULAR DETERMINATION OF SEX. 
surface epithelium, if denuded, is replaced by prolifera- 
tion of the cells lining the uterine glands and the thick- 
ened, oedematous condition of the membrane rapidly 
subsides during a period of six or seven days. While 
the escape of blood takes place only from the surface of 
the uterus, the other reproductive organs-the ovary, 
the Fallopian tubes, and even the external genital organs 
-share to some extent in the vascular congestion ex- 
hibited by the uterus during the period preceding the 
menstrual flow. The mucous membrane of the uterus 
may be said to exhibit a constantly recurring menstrual 
cycle which falls into four periods: 
" (i) Period of growth in the few (5) days preceding 
menstruation, characterized by a rapid increase in the 
stroma, blood-vessels, epithelium, etc., of the membrane. 
(2) The menstruation or period of degeneration 
(4 days), during which the capillary hemorrhage takes 
place and the epithelium suffers degenerative changes 
and is cast off more or less. 
" (3) The period of regeneration (7 days), during 
which the mucous membrane returns to its normal size. 
" (4) The period of rest (12 days), during which the 
endometrium remains in a quiescent condition." 
The above division of the menstrual cycle into definite 
periods was undoubtedly made from the author's per- 
sonal observation of very many cases. The period of 
menstruation and regeneration corresponds to the time 
of uncleanness of the woman in the Mosaic law, during 
which time insemination is forbidden. While Howell 
made his observations from those who reside in a temper- 
ate climate between 350 and 450 north latitude, the 
Mosaic law was given to those who were acclimated to MENSTRUATION. 
135 
the region south of 200 north latitude. As the conditions 
peculiar to menstruation are handed down to the off- 
spring, the observance of the law of Moses was still 
necessary, although his people had been transplanted 
to a more temperate climate; for in the warmer region 
urethritis follows the act of insemination during this 
period. 
After carefully studying this problem, it seems logical 
to regard the period of rest as the physiological period 
for the reception of the fertilized ovum, and no doubt 
nature has decreed that it should take place during this 
period. 
Relation between Menstruation and Ovulation.- 
Nature has designed that ovulation should take place 
just prior to, or during, the period of rest in the uterus. 
At this period the cilia of the epithelium are more sen- 
sitive, more active, and more powerful. Their move- 
ments create a current in the mucous secretion both in 
the uterus and in the Fallopian tubes. This current 
carries the ovum from the fimbriated extremity of the 
Fallopian tube to the uterine cavity, and the mucous 
secretion from the uterus to the vagina. The truth of 
this statement has been proved several years ago by 
Hofmeier, who showed that the ciliary motion was all 
in the same direction, toward the outlet of the uterus. 
This current, set up by the ciliated epithelium, prevents 
the fertilization of the ovum by the deformed and 
decrepit spermatozoa. The more rapid the current, the 
more rapidly the spermatozoa would have to move to 
make search for the ovum and maintain their position. 
In this most peculiar mechanism, we have the greatest 
safeguard to the animal kingdom, for it insures fertiliza- 136 
THE CELLULAR DETERMINATION OF SEX. 
tion by active spermatozoa, and goes far to keep the tubes 
and the uterine cavity in an aseptic condition. The 
beginning of menstruation is the announcement of the 
rupture of the wall proper of the Graafian follicle, formed 
from the stroma of the ovary; this probably allows the 
extrusion of part of the follicular secretion into the 
stroma of the ovary, which produces inflammation of 
the gland and establishes menstruation. On account of 
its delicate structure, one is led to anticipate a rupture 
of the inner tunics of the follicle and the escape of at 
least part of its contents, on rupture of the capsule 
derived from the ovarian stroma. The surface of the 
ovaries of the old woman is covered with cicatricial 
tissue, and when the tunics derived from the stroma of 
the ovary rupture, the follicle is prevented from migrat- 
ing to the surface of the ovary by the tough scar tissue, 
and in this case the contents of the follicle are extruded 
into the stroma of the ovary. The follicular secretion 
is gradually absorbed, which gives rise to dystocia and 
menorrhagia in the older woman. 
The time required for the maturation of a Graafian 
follicle and its ovum during sexual life depends upon the 
individual, her general health, and her environment. A 
normal woman, under normal conditions, who is not 
subjected to anything unusual, will mature the Graafian 
follicle in the time given under the maternal secondary 
laws (page 206). At the age of twenty-four the human 
female will normally mature the Graafian follicle midway 
between the last day of one menstrual flow and the first 
day of the anticipated menstruation. The development 
of anything unusual in or about the woman may cause 
either delay or premature rupture of the Graafian follicle. MENSTRUATION. 
137 
Premature rupture or rupture after maturity may be 
caused by coition, or by a great desire for it, or by 
psychical or ocular impressions which produce a flow of 
blood to the sexual organs. Constipation with resultant 
straining at stool, difficult micturition, coughing, singul- 
tus, lifting, or any physical exertion which would cause 
a forced contraction of the abdominal muscles; retention 
of a large quantity of urine causing distention of the 
bladder, or the retention of fecal matter causing disten- 
tion of the sigmoid flexure of the colon, either or both of 
which latter conditions are liable to produce direct or 
indirect pressure against the ovary; increased blood- 
pressure produced by a cold bath, or cold acting on the 
body and forcing the blood from the peripheral blood- 
vessels to the internal organs; the taking of an unusual 
quantity of easily assimilable food, which would increase 
the blood-pressure and augment the contents of the 
abdominal cavity-either one or several of these acting 
together may give such an impetus as would rupture a 
Graafian follicle near its maturity. Ergot, digitalis, etc., 
would probably produce the same result. 
The fact that menstruation is the announcement that 
a Graafian follicle has developed to maturity is beauti- 
fully demonstrated in the bitch, in the elephant, and in 
some cows, in which oestrum appears only once in from 
three to six months. Upon insemination the female dog 
delivers her young in sixty-three days; the elephant 
delivers her young in eighteen to twenty-two months, 
and the cow in nine months. I consider this positive 
proof that the ovum from the Graafian follicle which 
set up the menstruation is the ovum fertilized in the 
human species, and not the ovum from the first missed 138 
THE CELLULAR DETERMINATION OF SEX. 
menstruation. Or, in other words, the ovum extruded 
from the Graafian follicle which set up the menstruation 
is the only ovum found in the Fallopian tubes or uterus 
until after a succeeding menstruation, assuming the 
woman to be in a normal condition. In all these 
cases, it is impossible for the ovum from an anticipated 
oestrum to be present at this period. In the female dog, 
the number of the young can be regulated by preventing 
copulation until the lapse of twelve or fourteen days 
after the beginning of the oestrum, since by so doing only 
one or two pups are generally born; but, if copulation 
takes place immediately or soon after the beginning of 
oestrum, from five to eight pups are usually produced. 
This demonstrates beyond question that the ova which 
set up the oestrum are the ones fertilized; furthermore, 
that not all the Graafian follicles come to maturity in 
the same female dog at the same time during the same 
oestrum; and finally that only some of the ova may be 
fertilized, while the others from the Graafian follicles 
which ruptured earliest escape. But if copulation be 
delayed, one could not hope to produce female pups, in- 
asmuch as the spermatozoa would not have to wait for 
the ova and fertilization would take place almost imme- 
diately. The spermatozoa with large heads, excepting 
those described on page 69, are more active than those 
with small heads or nuclei; accordingly they proceed 
rapidly, keep in advance of the crowd in search for the 
ova, and pass through mucous secretions flowing in a 
swift current; while, on the other hand, the old, slower, 
small-headed female-producing spermatozoa are left be- 
hind in the race. In some exceptional cases a Graafian 
follicle which set up menstruation may not be ruptured MENSTRUATION. 
139 
until after a succeeding catamenia, and in such a condition 
it would probably rupture during or soon after the flow. 
According to Oldham, as quoted by Barnes, the ovaries 
enlarge for about four days, remain stationary for about 
three days, and then gradually subside. It has also 
been ascertained that the enlargement commences as a 
rule shortly before the menstrual period, that it attains 
its maximum about the time of the flow, and that it 
subsides after the menstrual hemorrhage (Robert Barnes 
and Fancourt Barnes). " Both enlargement and sub- 
sidence are periodically recurring processes, and their 
periods correspond so closely that ovulation and menstru- 
ation occur simultaneously. However, although this 
may be, and probably is, the rule, yet it is far from being 
an invariable one " (Barnes). 
The human ovary is covered by short columnar 
epithelium derived from the peritoneum, inside of which 
are the Graafian follicles containing the ova. Each 
Graafian follicle contains an ovum and an epithelial 
envelope, and in the smallest follicles the ovum is small, 
the epithelial envelope consisting of a single layer of 
small cells, which may be flattened. In the larger 
follicles the epithelial cells are in two layers, and these 
are columnar in shape. In the largest Graafian follicles, 
each of these layers is formed of several strata of cells, 
and fluid may collect between these layers at any point. 
The discus proligerus immediately surrounds the ovum 
and forms the internal layer, while the outer layer lines 
the cavity of the follicle and is known as the membrana 
granulosa. The Graafian follicle gradually becomes 
larger and the fluid increases in quantity until it produces 
rupture of the theca folliculi; this is probably followed 140 
THE CELLULAR DETERMINATION OF SEX. 
by the escape of a small quantity of the follicular secre- 
tion through the inner tunic out into the stroma of the 
ovary, where it is absorbed. It is very probable that 
the absorption of this secretion produces inflammation 
of the ovary and the establishment of menstruation. 
The size of the Graafian follicle still increases until the 
tunica albuginea, finally yields. The migration of the 
follicle through the tunica albuginea undoubtedly con- 
sumes from ten days to three weeks. The ovum, having 
passed into the medullary part of the ovary from its 
surface, carries before it a certain quantity of stroma 
tissue, which is later reinforced with blood-vessels and 
prevents the rupture of the theca folliculi on its medul- 
lary surface. Therefore rupture of the theca folliculi 
takes place at the stigma, the point of least resistance, 
which is always nearest the place from whence the 
Graafian follicle entered the ovary. When rupture 
of the theca folliculi occurs, a part of the follicular 
secretion is extruded into the stroma of the ovary from 
the point of rupture, and as soon as the follicle ap- 
proaches and comes into contact with the tunica al- 
buginea, further escape of the secretion is cut off by the 
support rendered the tunica granulosa by its contact 
with the albuginea. Now that the follicle is in contact 
with the tunica albuginea it is carried before it as the 
follicle increases in size, and accordingly the tunica 
albuginea diminishes in thickness until the follicle is at 
last ruptured. As soon as the escape of the follicular se- 
cretion is cut off by its contact with the tunica albuginea, 
inflammation of the ovary subsides, and the normal 
condition is resumed. If, however, the follicle on its 
migration to the surface of the ovary comes into contact MENSTRUATION. 
141 
with dense, tough scar tissue the escape of the follicular 
secretion may continue and progress of the follicle to 
the surface of the ovary be prevented, in which case it 
would undergo absorption and degeneration. As Schafer 
says, " Some of the Graafian follicles do not burst, but 
after attaining a certain stage of maturity undergo a 
process of retrograde metamorphosis and eventually 
disappear." The latter condition would occur only 
occasionally in the young female, though it is probable 
that it frequently occurs in older women and gives rise 
to dysmenorrhcea often met with in them. We can now 
readily understand why dysmenorrhcea may be attended 
by great variation in the maturation of the Graafian 
follicles. The point which I wish to make clear is the 
fact that rupture of the Graafian follicle does not nor- 
mally occur until from five to sixteen days after the 
menstrual flow, and that, when the Graafian follicle is 
ruptured, the ovum is normally propelled into the uterine 
cavity in six or eight hours. I furthermore state that 
the ovum does not usually remain in the Fallopian tube 
longer than from three to six hours. The time required 
for the ovum to reach the Fallopian tube after its ex- 
trusion from the Graafian follicle will always be prob- 
lematical. It will vary in the same individual, and there 
is no way to prevent it except by gravitation (see page 
46). It has been stated that " in order to reach the 
uterus the ovum has to pass through the whole length 
of the Fallopian tube, that this passage probably takes 
at least eight days before it is completed, and that 
fertilization takes place during the passage of the ovum 
through the Fallopian tube " (Barnes). If fertilization 
of the ovum generally occurred in the Fallopian tube, 142 
THE CELLULAR DETERMINATION OF SEX. 
and it took eight days for the ovum to make its passage 
through it, then tubal pregnancy would be rather fre- 
quent. Of course, it is not known just when maturation 
of the ovum is accomplished, but it is not necessary for 
the ovum to pass through the Fallopian tube and to 
reach the uterine cavity before fertilization takes place; if 
it were, such a thing as extrauterine pregnancy would be 
unknown. It is most likely that the relief of the general 
and uniform pressure on its extrusion from the Graafian 
follicle is soon followed by the maturation process or 
the formation of the polar bodies in the fully developed 
ovum. We should anticipate a delay in the formation 
of the polar bodies in undeveloped ova, when removed 
prematurely from the follicle. When maturation of the 
ovum has been accomplished, cell division is ordinarily 
resumed immediately upon fertilization; that is, under 
favorable conditions, which are always present in 
mammals. As soon as cell division begins, there is a 
general tendency on the part of the ovum to take up the 
more fluid constituents of the zona pellucida and of its 
immediate investment. The more solid tenacious con- 
stituents of the mucus surrounding the ovum are thus 
left without, and soon the cilia are powerless to move it. 
The cilia adhere to this tenacious and rapidly dwindling 
envelope of the ovum; and the latter, unless forced 
away by something more powerful than the cilia, remains 
in its present location. At this juncture, however, the 
peristaltic motion of the Fallopian tube may be set up 
and the onward movement resumed until the ovum shall 
have been forced into the uterine cavity. Many of the 
more recent authors concur in this opinion and give 
statistics which show that the extrusion of the ovum MENSTRUATION. 
143 
from its Graafian follicle does not take place in very 
many cases until several days after the cessation of 
menstruation. 
A Graafian follicle is not mature until it can be 
ruptured by orgasm in the female. As a rule, the 
maturity of a Graafian follicle is not complete until from 
seven to fourteen days after the last day of the menstrual 
flow. In those women whose menstruation is irregular 
and delayed from thirty-five to sixty days or longer, it 
is probable that the Graafian follicle does not mature 
until from ten to sixteen days after the last day of the 
menstrual flow. Normal menstruation is sometimes 
succeeded by a second blood-flow within a day or two 
after the cessation of the normal menstrual flow. This 
second flow of blood is probably due to the rapid advance- 
ment to maturity of another Graafian follicle. In all 
these cases there are two Graafian follicles and their ova 
to be considered in sex control. When it is desirable to 
produce a male child in these cases, the date for insemina- 
tion must be calculated from the last day of the last flow 
and to compensate for the excessive loss of blood, add 
two or three days to this date. The loss of blood delays 
the maturation of the Graafian follicle, and due time 
must be allowed for this. 
The presence of a mature Graafian follicle in the ovary 
serves to create a desire for cohabitation on the part 'of 
the female, for her state is analogous to that of the male 
when the vesiculae seminales are filled with semen. The 
assertion made by some women, and accepted by a few 
obstetricians, that a peculiarly pleasurable sensation 
attends fruitful intercourse, as given by Parvin, is 
undoubtedly to be explained by the rupture of a Graafian 144 
THE CELLULAR DETERMINATION OF SEX. 
follicle during orgasm, which relieves the female of 
further desire for intercourse, and the chance for preg- 
nancy is at its maximum when rupture of a Graafian 
follicle takes place during cohabitation. CHAPTER VII. 
THE PROCESS OF INSEMINATION. 
By insemination is meant the deposition of the seminal 
fluid within the genital tract of the female during the 
sexual union. Before conception can take place there 
must be a union and fusion of a spermatozoon with an 
ovum. When this occurs, the woman conceives and 
enters upon the period of pregnancy or gestation. When 
the semen is deposited in the genital tract the spermato- 
zoa make their way to the ovum by virtue of their inher- 
ent power of locomotion. Many theories have been ad- 
vanced to explain the method by which the spermatozoa 
reach the uterus, one of the oldest being that of Johann 
Muller, who thought that the semen was forced in by 
the piston-like action of the penis. Litzmann, Wernicke, 
and Beck advocated the aspiration theory, according 
to which the hood-like layer of the uterus contracts, 
forcing the cervix down into the lake of spermatic fluid; 
then, relaxation following, the semen is aspirated into 
the canal. Kristeller's idea was that the cervical canal 
was filled with a plug of mucus from the cervical glands; 
just as in the above theory, the uterus, contracting, 
pushes the mucous plug down into the semen, then 
relaxing, brings back the fertilizing fluid. Marion Sims' 
view has been received with the greatest favor. It is 
that the semen forms a lake in the posterior cul-de-sac, 
and, the cervix dipping into it, the fluid passes up the 
uterus. 
145 146 
THE CELLULAR DETERMINATION OF SEX. 
Nature has provided that a rigid contraction of the 
uterus shall take place at the moment of the female 
orgasm, squeezing out every drop of the old viscid, thick, 
and semisolid mucus. On relaxation of the uterus from 
the orgasm the uterine walls slowly refill with blood as 
in the normal condition; they do not become engorged 
with blood as they were during the sexual union prior 
to orgasm. The uterine cavity is refilled with the 
mucous secretion from the Fallopian tubes, and the 
similar fluid from the mucous membrane lining its cavity. 
Thus the uterine cavity contains a fresh, thin, limpid 
secretion, in which the spermatozoa can move freely and 
actively. No part of the ejected mucous secretion from 
the uterus or the semen is drawn back into the uterine 
cavity on relaxation of the uterus. The spermatozoa 
propel themselves through this fresh, thin, limpid fluid, 
but can make no headway through the old, thick, viscid 
secretion. The sexual union produces an engorged con- 
dition of the blood-vessels of the vagina, uterus, Fallopian 
tubes, and ovaries, and the congestion causes a copious 
flow of fresh thin mucus from all the mucous glands 
in these organs. Spermatozoa are repelled by thick 
tenacious mucus, for as soon as they attempt to make 
their way through it they become fixed. After ejacula- 
tion of the semen into the vagina the spermatozoa pass 
out of the seminal fluid into the fresh mucous secretion 
and make their way unaided to the ovule. " The capac- 
ity of the uterine cavity in the nulliparous is from two 
to three cubic centimetres, or from thirty-two to forty- 
nine minims; in the parous three to five cubic centi- 
metres, or forty-nine minims to one drachm twenty-one 
minims " (Parvin). THE PROCESS OF INSEMINATION. 
147 
When we consider the small capacity of the uterine 
cavity, we can readily understand why no part of the 
ejected fluid nor the semen is aspirated into the canal 
on relaxation, inasmuch as the " anterior and posterior 
walls are normally in contact, or else separated by only 
a thin layer of mucus " (Parvin). 
A proof of the truth of Marion Sims' theory is said to 
be furnished by the great infrequency of pregnancy in 
cases in which uteri, after operation, cannot dip into 
the spermatic fluid. Operations, however, usually leave 
scar tissue, and where there is cicatricial tissue there is 
an absence of glands and ciliated cells, therefore when the 
mucous secretion becomes lodged on scars, it remains 
more or less fixed and becomes very viscid, rendering the 
passage of the spermatozoa through it impossible. If the 
scar tissue encircles the os uteri, we can readily under- 
stand why it is almost impossible for the spermatozoa to 
pass it. Moreover, in case of extensive scar tissue at the 
mouth of the uterus, the mucus adhering to it prevents 
the uterus from freeing itself from the thick, viscid mucus 
which is ordinarily cast out during orgasm. There is 
no way, then, for the spermatozoa to avoid this thick 
viscid mucous secretion and to make their passage to the 
Fallopian tubes. The viscid mucus adheres tenaciously 
to the scar tissue which encircles the uterine canal and 
the orifice is corked with the same secretion, which has 
just been partially ejected from the uterus. When the 
female fails to reach orgasm, the old, thick, viscid mucous 
secretion remains in the uterine cavity and renders it 
difficult for the spermatozoa to make their way to the 
Fallopian tubes. The delay consumes the nutrition 
stored in the nuclei of the spermatozoa, the heads are 148 
THE CELLULAR DETERMINATION OF SEX. 
reduced in size and consequently rendered female-pro- 
ducing. Thus we understand how the tendency to 
female-production is augmented by failure of orgasm 
in the female during sexual union. CHAPTER VIII. 
THE CELLULAR BASIS OF THE DETERMINATION OF 
SEX IN THE HUMAN SPECIES. 
Primary Law.-1st. The production of a male. 
2d. The production of a female. 
1st. The production of a male from the spermatozoon 
and ovum. When the sex-membrane covers less than 
one-half of the nucleus (Fig. 16), that membrane does not 
come into contact or clash with the vitelline membrane 
when the spermatozoon enters the cytoplasm of the ovum 
for the reason that it is posterior to the greatest circum- 
ference or diameter of the nucleus. The nucleus, by 
making a larger opening through the vitelline membrane 
into the cytoplasm of the ovum, prevents the sex-mem- 
brane from coming into contact or clashing with any 
obstruction. The nucleus of an ultra active spermato- 
zoon passes through the vitelline membrane, carrying 
with it both body and tail regardless of the sex-membrane 
covering more than its posterior half. In any event 
the nucleus, the body, and the tail all enter into the 
cytoplasm of the ovum and a male is produced. 
2d. The production of a female from the spermatozoon 
and ovum. When the sex-membrane covers more than 
one-half of the nucleus (Fig. 17), it comes into contact 
and clashes with the vitelline membrane. Even if the 
membrane is but partially stripped off the nucleus, a 
small quantity of the cytoplasm of the ovum flows in be- 
149 150 
THE CELLULAR DETERMINATION OF SEX. 
Fig. 38.-The Production of a Male Rat Zygote, as Witnessed by Sobotta. 
(Description on opposite page.) CELLULAR BASIS OF SEX DETERMINATION. 
151 
tween the sex-membrane and the nucleus. Here the 
cytoplasm comes into contact with the two or three small 
filaments which pass from the end-knobs of the centro- 
Fig. 39.-The Production of a Female Bat Zygote, as Witnessed by Van 
der Strict. 
(Slightly modified.) 
The development of the sperm-nucleus from the head of the spermatozoon is very 
evident in this case, because the rest of the spermatozoon happens not to have been 
thrown off. 
some in the body to the inner structure or smaller centro- 
some in the nucleus, liquefying them almost instantly, 
Fig. 38-A, Maturation of the ovarian egg still partially surrounded by the follicle- 
cells and the membrane (z.p, zona pellucida); the polar spindle-formed. B, Ovum 
immediately after fertilization (sperm-nucleus at (J). C, After the first stage 
figured it is impossible to determine which of the two nuclei represents the male or 
the female pronucleus. J, Female pronucleus; male pronucleus; p.b. B and 
p.b. C, polar globules. D, Germ-nuclei approaching, of 'equal size. E, The 
chromosomes forming. F, The small cleavage-spindle in the centre; on either side 
the paternal and maternal groups of chromosomes. G and H, Last stages of 
nuclear cleavage. (Sobotta.) 152 
THE CELLULAR DETERMINATION OF SEX. 
when the body and the nucleus become disengaged. In 
consequence the body, the sex-membrane, and the tail are 
left outside the cytoplasm. The vitelline membrane is a 
very elastic membrane, and when the nucleus pushes 
through it, the latter is hugged so tightly that the sex- 
membrane is stripped off during the passage. When the 
body of the spermatozoon fails to pass into the cytoplasm 
of the ovum a female is produced. 
Proof of the Above Statement.-This is the only con- 
ceivable method by which nature could draw a sharp 
line of demarcation, and one perfect in its working in 
the spermatozoa of the vertebrate animals. To under- 
stand this, is to understand why there are not more true 
hermaphrodites than the few on record. We can see 
that a half-way position is a thing almost impossible. 
The perfection of this method of sex determination is 
demonstrated and proved by the whole animal kingdom. 
The next best proof of this biological law is furnished 
by several human eye witnesses of its occurrence. 
Sobotta, who was probably the first person to witness 
the production of a male rat, gives the following: "A 
spermatozoon makes its way through the vitelline 
membrane, becomes embedded in the cytoplasm of the 
ovum, and its tail is quickly absorbed by the cytoplasm 
while its nucleus and probably the middle piece persist 
as distinct structures" (Fig. 38). The production of 
the female has often been witnessed. One of the best 
illustrations, which is that of a bat, is given by Van der 
Strict (Fig. 39). The development of the sperm- 
nucleus from the head of the spermatozoon is very 
evident in this case, because the rest of the spermatozoon CELLULAR BASIS OF SEX DETERMINATION. 
153 
is still on the outside and happened not to have been 
thrown off. 
The above citations furnish what I consider absolute 
proof of this great law, and how it can be construed 
otherwise is more than one could comprehend. 
Fig. 40.-Spermatozoa of Bat. 
(Vesperugo.) 
Fig. 41.-Spermatozoa of Raja 
/Anterior Part). 
Fig. 40.-1, Male-producing spermatozoon; 2, female-producing spermatozoon; 
n, nucleus; b, body; t, tail. 
Fig. 41.-1, Male-producing spermatozoon; 2, female-producing spermatozoon; 
a, acrosome; n, nucleus; _b, body; e.p, end-piece. 
The point next to be considered is, Is this a general 
law and are the spermatozoa anatomically so shaped 
that the result would be the same in all animals as well 
as in man? An affirmative answer can be given in the 
case of the following: Sturgeon and pike (cuts by 
Wilson from Ballowitz.) Both of these fishes could be 154 
THE CELLULAR DETERMINATION OF SEX. 
governed by this law; for in the case of the sturgeon the 
nucleus is shown to be smaller than the middle-piece, in 
which instance a female would be produced. As soon 
as the nucleus made its way through the vitelline mem- 
brane the middle piece, since it is larger than the nucleus, 
would clash with that membrane, so that it would be 
pushed back from the nucleus and expose the small fila- 
ments connecting the body to the head, while at the same 
time the cytoplasm of the ovum would flow in between 
the nucleus and the middle piece, the filaments would be 
immediately liquefied and separate the nucleus from the 
middle piece. In the case of the pike, in which the 
nucleus shown is larger than the middle piece, a male 
would be produced (Fig. 42, 1).* In the Raja (Fig. 41), 
the insect (Calathus) (Fig. 44), the bullfinch (Fig. 43), 
the bat (Fig. 40), the nucleus and the middle piece are 
so shaped that the introduction of the nucleus may take 
place very readily without the middle piece, as has 
already been explained (Fig. 43, B 2). 
The fact that only one sex comes from an egg or ovum 
is further proof of this law. " In man twins may be 
born and these twins may be of two kinds. First, those 
that are developed from two different eggs, each of which 
has its own chorion and develops its own placenta. This 
kind may be designated as false twins, and in the matter 
of sex they may be male and female, or both male, or 
both female. The matter varies as in the statistics of 
births in general. In the other group, however, of true 
twins or identical twins, the two embryos are developed 
* It is probable that the spermatozoa of the fish family are in a 
general way shaped anatomically like those just described, and 
would be subject to the same physiological law of fertilization. CELLULAR BASIS OF SEX DETERMINATION. 
155 
from a single ovum and are included in a single chorion. 
In such cases the sex of the twins is always the same, they 
are both boys or both girls " (Howell). On this point 
Montgomery says: "We come now to the inquiry of what 
processes determine that an egg shall develop into a male 
i, Pike, male-producing spermatozoon; 2, sturgeon, male-producing sperma- 
tozoon; 3, female-producing spermatozoon of the sturgeon; a, acrosome; n, nu- 
cleus; s.m, sex-membrane; t, tail. 
Fig. 42.-Spermatozoa of Fish. 
or a female individual. And just here it is to be noted 
that the sex of the individual is probably determined not 
later than the stage of fertilization of the egg. This is 
to say, despite the numerous experiments made in the 156 
THE CELLULAR DETERMINATION OF SEX. 
hope of securing positive results, it has not yet been 
possible to alter the sex ratio by external influence acting 
after the one-cell stage of the organism. The nearest 
approach to securing this end has been reached by Shull 
(1910), who found that by altering external conditions, 
Fig. 43.-Spermatozoa of Bullfinch. 
B.i, Male-producing spermatozoon; B.2, female-producing spermatozoon; a, 
acrosome; n, nucleus; m, the body; I, part of the tail. 
namely, composition of the water, the relative numbers 
of male-producing and female-producing individuals can 
be changed in Rotatoria. The main result reached after 
much experimentation and discussion is that the sex of 
the individual is probably established not later than the 
stage of fertilization; and there is still no body of evidence 
that the sex state so established can be changed by in- CELLULAR BASIS OF SEX DETERMINATION. 
157 
fluences acting during a later stage. In this connection 
may be noted the interesting cases of polyembryony, 
where several embryos come from the same egg. This 
has long been known for trematodes and cestodes, more 
recently for some parasitic wasps (Marshal, 1904, Sil- 
Fig, 44.-Spermatozoa of Insect (Calathus). 
4.1, Female-producing spermatozoon; A. 2, male-producing spermatozoon; n, 
nucleus; s.m, sex-membrane; t, part of the tail. 
vestri, 1906), and has been made known within the year 
for the armadillo by Newman and Patterson. In these 
cases all the embryos from one egg are of the same sex, 
which shows that the sex feature must be stamped in 
the organism very early." 
In the lower forms of animal life, as the hermaphrodite, 158 
THE CELLULAR DETERMINATION OF SEX. 
the line of demarcation between the nucleus and the 
middle piece of the spermatozoa is not constructed 
anatomically so that the introduction of the nucleus 
could take place unaccompanied by the middle piece. 
For this reason, they have not advanced to the higher 
form of sexual reproduction. 
In heteroparthenogenesis both sexes are produced from 
unfertilized eggs as in Aphides, Rotatoria, and Daphnids. 
The Aphides (plant-lice), while living under favorable 
conditions of nutrition, produce only females the eggs 
of which develop parthenogenetically. In the autumn, 
under less favorable conditions, males as well as females 
are produced; and in the favorable environment of a 
greenhouse the production of females alone may continue 
for years. In the Hydatina, the sex is determined at a 
very early period, before the egg is laid; the eggs being 
of two sizes, of which the smaller give rise only to males, 
and the larger only to females. Here again the well-fed 
females produced a preponderance of female offspring, 
and vice versa. The eggs laid during the favorable 
environment, when the females are well fed, are large, 
female-producing parthenogenetic eggs. It is during 
this period that the nurse cells of the eggs in the ovaries 
are able to furnish to the ovum all nutriment necessary 
for its production, and in abundance, which is demon- 
strated by the size of the eggs. In this event the quantity 
of the fertilizing element (found in the middle piece of the 
spermatozoa) is insufficient to produce male offspring. 
In a less favorable environment, when the food becomes 
scarce, the nurse cells are unable to take up from the 
circulation sufficient nutrition for the production of eggs, 
in which event the nurse cells themselves are engulfed CELLULAR BASIS OF SEX DETERMINATION. 
159 
and taken into the cytoplasm of the ova, when their lives 
are sacrificed for the production of ova. In this way the 
ovum receives from the nurse-cell body sufficient of the 
fertilizing element to produce a male. That the bodies 
of the nurse cells are taken into the cytoplasm of the ova 
and the life of the nurse cells sacrificed for the production 
of ova has been proved and is beautifully shown in the 
Hydromedusa Cladonema, in an observation published 
by Weismann. 
In homoparthenogenesis only one sex is produced 
from unfertilized eggs, which may be arrhenotoka or the 
formation of males, as in the honey bee, or thelytoka or 
the formation of females alone, as in the moths. When 
the nurse cell is engulfed by the ovum it would probably 
contain more of the material entering into the formation 
of the aster, which stimulates cell-division and the forma- 
tion of the second polar body, thus eliminating its burden- 
some quantity of chromosomes and at the same time the 
dynamic power is not lessened. Formation of the second 
polar body in all unfertilized parthenogenetic eggs is 
followed by the production of males. In the formation 
of the second polar body one-half of the chromosomes 
characteristic of the female are eliminated; if this is not 
fertilized a male is produced. Male-production is caused 
by the reduction of the chromosomes in the zygote. 
This eliminates the chromatin which is the burden that 
slows down cell-division, giving rise to female-produc- 
tion. If, in the event the egg is fertilized after the for- 
mation of the second polar body, the chromosomes (the 
burden) are restored, the result is female-production. In 
fertilization of the parthenogenetic eggs the nucleus only 
is added. Thus the aster-forming substance (the centro- 160 
THE CELLULAR DETERMINATION OF SEX. 
some) is the same in quantity, while the chromosomes 
vary; there being less in male-production. In the 
vertebrate the chromatin is constant in quantity, while 
the centrosome (aster-forming substance) varies, there 
being a larger centrosome in the male-production. 
In W. E. Castle's contribution from the zoological 
laboratory of the museum of comparative zoology at 
Harvard College he says: " With a single exception to 
be discussed presently, we know that in uninterrupted 
parthenogenetic reproduction, as it occurs, for example, in 
the Daphniae and Rotifera at certain seasons of the year, 
the parthenogeneticegg forms only one polar cell, and the 
animal developing from such an egg is invariably female, 
the male character being recessive. In other words, the 
daughter produced by parthenogenesis is exactly like the 
mother. No segregation of sex-characters has taken 
place in her development. That the male character is 
still present in the agamic female is known from the fact 
that such a female retains the capacity to produce males 
under appropriate external conditions. 
" At the return to sexual reproduction, the partheno- 
genetic mother produces eggs which form a second polar 
cell, and from such eggs (if unfertilized) only males de- 
velop. It is clear, then, that in the second maturation 
division the female character has been eliminated from 
the egg, for were it still present there, it must from its 
nature dominate. 
" In the honey-bee, all the eggs, without exception, 
form two polar bodies, and the unfertilized egg invariably 
develops into a male. Accordingly a queen bee which 
has not copulated can produce only male offspring. But 
one which has copulated produces both male and female CELLULAR BASIS OF SEX DETERMINATION. 
161 
offspring, the former, however, only from unfertilized 
eggs, the latter always from fertilized eggs. 
" In parthenogenetic rotifera and Crustacea, under 
favorable external conditions, the egg develops straight- 
way after the formation of a single polar cell, usually 
while still within the body of the mother, and without 
awaiting the occurrence of a second maturation division. 
No segregation of sex characters has yet occurred within 
the egg, which develops, without the necessity of fertiliza- 
tion, into an agamic female like the mother. If, however, 
external conditions are unfavorable, the egg will not pro- 
ceed to develop until it has undergone a second matura- 
tion division. The egg is then capable of development 
either with or without fertilization. If it is not fertilized, 
as must necessarily be the case unless the mother has 
copulated, development takes place at once without the 
body of the mother, and a male is produced; but if the 
egg is fertilized, it takes up yolk and acquires a resistant 
shell, which ordinarily prevents its development until 
the following season; that is, it becomes a ' winter egg.' 
From such eggs there hatch invariably agamic females." 
In the Heterakis, Lygacus and Euschistus, and this 
whole series of species the size, quality, and power 
of the centrosome, or that part of the cell from which 
the aster is produced, are the same in either the male 
or the female. The difference in the zygote of these 
animals is simply the greater number of chromosomes in 
the female and at least one less in the male. The number of 
chromosomes may vary in either the ova or spermatozoa, 
the effect of which is precisely the same as adding just a 
little larger centrosome to a given quantity of chromatin for 
the production of a male. 162 
THE CELLULAR DETERMINATION OF SEX. 
" In Heterakis, for example, all the mature eggs re- 
ceive five chromosomes, while half the spermatozoa 
receive five and half but four. A moment's consideration 
shows that the characteristic diploid combination of the 
male will rise upon fertilization of the egg by a sperma- 
Zygote=Male 
Maturation 
Division 
Spermatozoa 
Polar Body 
Y -class 
Oogonium 
Socrmatogonium 
Mature Egg 
X-class 
Zygote-Female 
Fig. 45. 
tozoon of the ' Y '-class (lacking X), the female combina- 
tion upon fertilization by a spermatozoon of the ' X '- 
class. Fig. 45 shows this in diagram, and the result may 
be formulated as follows: 
Egg X + spermatozoon no X = Zygote X (male), 
Egg X + spermatozoon X = Zygote XX (female), 
the nucleus being otherwise of identical composition. 
"In the type represented by Lygacus or Euschistus, 
where a Y-element (' small idiochromosome ') accom- 
panies the X (' large idiochromosome ') the same con- 
clusion is shown even more clearly; for in many species 
the Y-element is the smallest of all the chromosomes and 
is therefore readily recognizable. In all such cases- 
as was first shown by Miss Stevens in the Coleoptera 
and the writer in the Hemiptera-this chromosome is 
confined to the male, while in the female its place is taken CELLULAR BASIS OF SEX DETERMINATION. 
163 
by a second X-chromosome (' large idiochromosome '). 
The female diploid groups contain accordingly XX, the 
male XY (being otherwise identical); and upon reduction 
each mature egg contains one X, and half Y. Obviously, 
therefore, the same fertilization-formulas apply as in the 
former case, if Y be inserted in its proper place, i.e., 
Egg X + spermatozoon Y = XY (male), 
Egg X + spermatozoon X = XX (female). 
The result is still more strikingly shown in cases where 
the X-element consists of two or more components. 
Whatever be their number in the diploid group of the 
male-two in Syromaster or Fitchia, three in Prionidus 
or Sinea, four in Gelastocoris-twice this number appear 
in the female groups. Thus the general formulas X + 
X = Female and X + Y male (in which Y may = zero) 
are applicable to the chromosome-combinations charac- 
teristic of the two sexes throughout this whole series of 
species, whatever be the composition of the X element " 
(Wilson). 
In comparing the size of male and female, the male is 
almost without exception the larger, although both male 
and female may have been reared in the same environ- 
ment, and with all the food of the same quality either 
could consume. In the human family the average 
weight for the male, according to my statistics, is 155 
lbs., that of the female 127 lbs. These are the average 
weights of one thousand married women and men. In 
the bovine family the difference is still greater: while 
the weight of a cow is from 600 lbs. to 900 lbs., the 
weight of a bull is from 900 to 1800 lbs. This great 
difference is not caused by the stimulus produced by the 164 
THE CELLULAR DETERMINATION OF SEX. 
absorption of spermatozoa, as the castrated bull (a steer) 
will reach the same size as the bull, thus demonstrating 
the inefficacy of the absorption of spermatozoa to stimu- 
late growth; neither will the removal of the ovaries 
stimulate growth in the female to the size of the male. 
All of these conditions prevail throughout the mammal 
group of animals. In the bird group of animals, the 
male is larger than the female: in the common fowl, the 
weight of the male is from 8 to 12 lbs., that of the female 
from 4 to 8 lbs. In the turkey, the weight of the male is 
from 10 to 20 lbs., that of the female from 6 to 11 lbs. 
The capon will grow to the same size as the cock, while 
the removal of the ovary will not stimulate the growth 
of the hen. This law should apply equally to the reptile 
and fish groups of animals, but it will be very hard to 
prove, because the male is subjected to different con- 
ditions from those acting upon the female. Moreover, 
in the fish family it will he hard to determine the sex 
in the young, and to give both an equal chance for de- 
velopment. The underlying cause in the production 
of males and females must of necessity be decided and 
powerful, to effect such a great difference in the manifes- 
tation of cell life. The cell of a large animal is no larger 
than that of a small animal, but the large animal's body 
contains more cells. 
This great difference is produced by the introduction 
of the middle piece or body along with the nucleus of the 
spermatozoon. The fact that the nucleus or head is 
necessarily larger and the entire spermatozoon younger 
when a male is produced, may possibly account for the 
stimulus to a greater cell production in the male. The 
middle piece or body of the spermatozoon is a powerful CELLULAR BASIS OF SEX DETERMINATION. 
165 
stimulus to cell-production, and from it, apart of the 
attraction-sphere, at least the astral rays and the spindle- 
fibres are developed. Now that we know that the male 
receives this large portion of the spermatozoon and that 
the female does not, we can very readily understand 
why a male child inherits the sexual characters of his 
father, while the daughter does not. The male charac- 
teristics are handed down directly in this part of the 
spermatozoon, or at least they are developed by it. 
When this part of the spermatozoon enters the ovum 
a male is produced regardless of anything which may- 
take place afterward. This fact is unquestionable in the 
higher order of animals, and I seriously doubt whether 
it can be different in any of the lower animals. Mr. 
Charles Darwin gives some very valuable information 
along this line in " The Descent of Man," Part II., 
Sexual Selection. 
" Inheritance as Limited by Sex.-The equal trans- 
mission of characters to both sexes is the commonest 
form of inheritance, at least with those animals which 
do not present strongly marked sexual differences, and 
indeed with many of those. But characters are some- 
what commonly transferred exclusively to that sex in 
which they first appear. Ample evidence on this hand 
has been advanced in my work on ' Variation Under 
Domestication,' but a few instances may here be given. 
There are breeds of sheep and goat, in which the horns 
of the male differ greatly in shape from those of the 
female; and these differences acquired under domestica- 
tion are regularly transmitted to the same sex. As a 
rule, it is the female alone in cats which are tortoise-shell, 
the corresponding color in the male being rusty-red. 166 
THE CELLULAR DETERMINATION OF SEX. 
With most breeds of the fowl the characters proper to 
each sex are transmitted to the same sex alone. So 
general is this form of transmission that it is an anomaly 
when variations in certain breeds are transmitted equally 
to both sexes. There are also certain sub-breeds of the 
fowl in which the males can hardly be distinguished from 
one another, while the females differ considerably in 
color. The sexes of the pigeon in the parent-species do 
not differ in any external character; nevertheless, in 
certain domesticated breeds the male is colored different- 
ly from the female. 
" The wattle in the English carrier pigeon and the 
crop in the pouter are more highly developed in the male 
than in the female; and, although these characters have 
been gained through long-continued selection by man, 
the slight differences between the sexes are wholly due 
to the form of inheritance which has prevailed; for they 
have arisen, not from, but rather in opposition to, the 
wish of the breeder. In all the species of deer but one 
the horns are developed only in the males, though cer- 
tainly transmitted through the females and capable of 
abnormal development in them. In several kinds of 
antelopes only the males are provided with horns, while 
in the greater number both sexes bear horns. In the 
merino breed of sheep the rams alone bear horns. 
" In most of the species of the splendid family of the 
pheasants, the males differ conspicuously from the 
females, and they acquire their ornaments at a rather 
late period of life. The male and female peacock differ 
conspicuously from each other in almost every part of 
their plumage, except in the elegant head-crest, which is 
common to both sexes. The sexes of dogs do not differ, CELLULAR BASIS OF SEX DETERMINATION. 
167 
except that in certain breeds, especially in the Scotch 
deer hound, the male is much larger and heavier than 
the female." 
It is not only the size of the male that is thus influ- 
enced, for every cell in the entire structure, the contour 
of the body, weight, offensive and defensive appendages, 
color, shape and quantity of hair and plumage, may be 
and often are affected. 
Fertilization of the ova of the fish may take place in 
the Fallopian tubes, or after their extrusion from the 
body of the female fish. The " Encyclopaedia Britan- 
nica " states: ''Among fishes viviparous birth occurs 
more commonly: in some Teleosteans the young de- 
velop within the ovaries; in many sharks and dogfish 
the development takes place within the oviduct, and in 
one case (Mustelus alevis) an actual placenta is formed 
by the interdigitation of folds of the yolk sac with those 
of the oviduct. Even the terrestrial amphibians usually 
lay their eggs in water, yet in some types, notably the 
Alpine salamander (Salamandria atra), development 
takes place within the oviduct. That this is a clear case 
of adaptation to the eminently terrestrial environment 
has indeed been well shown by experiments in which the 
young larvae, taken from the parent and transferred to 
pond water, developed like ordinary newts." 
Almost all birds and reptiles are oviparous, the extinct 
Ichthyosaurus is the sole exception. Fertilization of 
the reptile ovum may take place either in the ovary or 
in the Fallopian tubes; however, this point has not been 
determined. Fertilization of the ovum in the whole bird 
family is almost sure to take place while the ovum is still 
in the ovary. The ovum of a bird grows to a very large 168 
THE CELLULAR DETERMINATION OF SEX. 
size while in the Graafian follicle and thus diminishes 
the thickness of the investing membrane of the ovary 
immediately covering the follicle, the discus proligerus, 
and the membrana granulosa to such an extent that it 
offers but little resistance to the long (from two to three 
times that of man), peculiarly shaped, active, sharply 
pointed heads of the spermatozoa which are often pro- 
vided with a sharp-pointed acrosome. Fig. 31 shows a 
case in which a spermatozoon pierced a red blood cor- 
puscle through its long axis. I saw this in a specimen 
of semen taken from a lacerated testicle of a rooster 
which had just been struck and killed by a train. In Fig. 
32 are specimens from the same rooster, showing the sex- 
membrane which has been detached from the nucleus. 
The spermatozoa of the fowl soon die under the cover 
glass; the best of them live only two hours and a half 
at the temperature of 85° Fahr. When the ovum or 
yolk enters the oviduct and passes through the first five 
or six centimetres of its length, where the mucous mem- 
brane is smooth and transparent, the yolk absorbs a 
certain quantity of fluid, which is increased as the egg 
passes through the first and second divisions of the tube. 
It is almost incomprehensible how the spermatozoa of a 
bird can live and maintain their position in this duct for 
eighteen days, when such an abundance of albuminous 
fluid is secreted by its lining membrane every day for the 
production of the egg. 
When a bird is mated from twelve to fifteen days prior 
to the maturity of the ovum in the ovary, the sper- 
matozoa encounter great resistance in perforating the 
thick membranes covering the ovum; thus they consume 
both time and energy, and are reduced both mechanically CELLULAR BASIS OF SEX DETERMINATION. 
169 
and physically to the female-producing quality. In 
other words, when a membrane is stretched from fifty 
to one hundred and fifty times its natural size it is more 
readily and easily pierced. Some male birds are very 
inactive sexually, in which case the semen accumulates 
in the vesiculee seminales, spermatic cord, and the 
seminiferous tubules in the testicle, all of which become 
filled with aged, female-producing spermatozoa before 
the secretion leaves the vesiculae seminales. This state- 
ment is confirmed by all observing men who breed fowl, 
and who know that an old inactive cock produces female 
offspring. In January, 1910, I purchased twelve common 
barnyard hens and one male fowl from one Mr. B. The 
ages of the hens ranged from two to four years, while the 
male was two or three years old, weighed nine pounds, 
and proved to be moderately active. They were placed in 
two Philo coops, six females in one and six females with 
the male in the other. They were fed as advised by Mr. 
Philo and very soon they responded with many eggs. 
Each hen was banded and numbered and kept confined 
in the coop; the male was kept in one coop with the six 
hens until the best layers were sorted out by the use of 
the U. S. trap nest in each coop. Among the twelve 
hens there were eight good layers that laid every day, and 
these were all placed in one coop and kept there by them- 
selves for thirty days, when all possibility of a previous 
fertilization of the eggs had passed. During this time 
some of the hens had stopped laying, and the others were 
mated. However, by close attention for a few days all 
were again laying and promptly mated as soon as they 
began to lay. The male fowl had been kept with four 
hens all along and had access to the laying hens only as 170 
THE CELLULAR DETERMINATION OF SEX. 
indicated. Now, according to all information I had on 
the subject, the spermatozoa should enter the oviduct 
and make their way to its upper section, where they 
should wait for a time until the ovum appeared, when 
some one of the spermatozoa should fertilize it. Accord- 
ing to this theory, the first eggs laid after mating should 
produce males, and those laid later females. The experi- 
ment showed quite a different result. The result was a 
run of males almost unbroken up to and including those 
eggs laid twenty-four days after mating. This indicated 
that fertilization of the ova followed soon if not immedi- 
ately after mating and that the sex was determined at 
that moment. I used two of the Cycle Hatchers, manu- 
factured by E. R. Philo, Elmira, N. Y., either of which 
holds fifty eggs. The trap nest was used, each egg was 
dated the day it was laid, and bore the same number 
as the hen that had laid it. All of the eggs from the 
eight hens were thus numbered and dated, stored away 
in cotton wool, in a room where there was neither fire 
nor ice, and allowed to remain until fifty had accumu- 
lated when they were placed in the incubator. The eggs 
laid for twenty-six days after insemination were thus 
stored and incubated. All went well with the first 
incubator until the seventh day, when something went 
wrong with the thermometer, the temperature fell, 
and it was not discovered soon enough to save the eggs. 
In the second and last incubation, only eleven were 
advanced far enough to enable me to distinguish the sex, 
and this was the result: Hen No. 67 laid on the 21st, 
23d, and 24th days after mating, and all the eggs pro- 
duced males; 25th, the same hen laid a female-producing 
egg. No. 71 laid on the 7th, 8th, nth, and 13th days CELLULAR BASIS OF SEX DETERMINATION. 
171 
after mating, and all the eggs were male. No. 70 laid 
on the 10th, 14th, and 18th days after mating, all eggs 
were males. No. 74 laid on the 24th day after mating, 
also a male. A very small quantity of chicks, but an 
immense quantity of knowledge. By using this simple 
method one can produce practically all male chickens. 
Any animal in the prime of life, as the male fowl in this 
instance, will produce spermatozoa that will retain the 
male-producing quality longer than at any other period 
of life. 
The rule, therefore, is: Isolate the hens until they 
begin to lay, then mate with a male in the prime of life, 
one that has been with a few hens all along, and most 
of your chickens will be male, excepting a very few. In 
such a case the spermatozoa are all young and male- 
producing, for the vesiculae seminales have been kept 
empty, the spermatic cord has been drained, this in turn 
has drained the seminiferous tubules, and the sperma- 
tozoa are young and active all along the seminal canal. 
When the spermatozoon passes through the oviduct to 
the Graafian follicle of the ovary it pierces the very thin 
membrane covering the ovum and fertilizes the egg, and 
when this has been accomplished the sex has been de- 
termined. If the middle piece of the spermatozoon is 
separated from the nucleus, the latter alone enters the 
cytoplasm of the egg, the middle piece remains outside, 
and a female is produced, while if the nucleus is large, 
the middle piece follows it into the cytoplasm of the 
ovum, and a male results. Now, in order to change 
the sex-producing quality of the cock above referred 
to, he was isolated for six weeks or longer and not 
allowed to mate; after that period the following hens 172 
THE CELLULAR DETERMINATION OF SEX. 
were mated in the order given, with the result given 
below. 
On the 3d day of April, 1910, the following hens, bear- 
ing bands numbered 66, 70, 71, 72, and 73, were mated 
with the cock, which had been kept isolated for more 
than six weeks. No male had had access to the hens for 
thirty-five days, when they were mated in the order 
given (see page 173). 
In the above experiment three hens were used to hatch 
the eggs; one hen taking all the eggs which had accumu- 
lated up to the 9th of the month, a second hen taking all 
those laid between the 9th and the 18th, and a third hen 
taking all those laid between the 18th and the 25th. 
While this is not so good a result as the farmer usually 
gets in number, it is as good as one could hope for in 
doing this work. The facts that the aged spermatozoa 
produce females and that the spermatozoa can become 
aged and female-producing while in the male generative 
organs are beautifully brought out. It will be evident, 
therefore, that the sex can be controlled in the bird 
family in a very practical way, and that almost all males 
or all females may be produced at will. 
The birds produced from the first eggs laid after mating 
are stronger, grow up faster, and make larger, healthier, 
and more thrifty birds. The first eggs laid after mating 
also hatch just a little sooner, and the chicks almost 
always consume all the albumen in the egg; they break 
the shell, very soon bounce out, look around, and act as 
if the whole world were made for them. On the other 
hand, the birds produced from the eggs laid in the latter 
part of the mating are hatched a little later, and many of 
them do not consume all the albumen in the egg, it is left CELLULAR BASIS OF SEX DETERMINATION. 
173 
First Mating. 
Second Mating. 
Third Mating. 
Fourth Mating. 
Fifth Mating. 
No. 71. 
No. 73. 
No. 72. 
No. 66. 
No. 70. 
I 
2 
3 
4 
Egg female 
5 
Egg female 
Egg X developed 
Egg female 
6 
Egg 
7 
Egg female 
Egg female 
8 
Egg female 
.... 
Egg X developed 
Egg male 
Egg male 
9 
Egg female 
10 
Egg female 
Egg male 
Egg 
11 ..... . 
Egg female 
Egg 
Egg male 
12 
Egg female 
Egg male 
13 
Egg female 
Egg 
Egg male 
14 
Egg male 
Egg female 
Egg 
Egg male 
15 
Egg non-fertile 
Egg female 
Egg 
Egg female 
16 
Egg non-fertile 
Egg male 
17 
Egg non-fertile 
Egg female 
18 
19 
Egg non-fertile 
Egg female 
Egg male 
20 
.... 
21 
Egg small germ 
Egg non-fertile 
Egg non-fertile 
22 
Non-fertile 
Egg non-fe-tile 
.... 
23 
Egg non-fertile 
Egg non-fertile 
24 
Non-fertile 
Egg non-feniie 
25 
April 3d, 1910, 5:30 p.m. 174 
THE CELLULAR DETERMINATION OF SEX. 
in the shell and lost. The birds, moreover, are slow to 
come out of the shell after it is first broken, are often too 
weak to make their way out unaided, and wait until some 
one helps them out. They are feeble and delicate, grow 
up slowly, and remain small and puny through life. By 
some care in mating, by selecting for hatching only the 
first four eggs from an old hen, and by breeding from 
these, the size of the birds could be doubled in a few 
generations. 
The dog, being a mammal, can be used to advantage 
in experimenting for the determination of sex, on account 
of the period of heat being well marked and lasting as 
a rule for several days. The phenomenon known as heat 
in the lower mammals resembles, in many essential re- 
spects, menstruation in human beings, and these func- 
tions may be regarded as homologous. Heat is a period 
of sexual excitement which recurs in the female dog at 
intervals of from twelve to sixteen weeks, though in 
some it may not occur oftener than once or twice in a 
year. The condition is accompanied by changes which 
resemble those of menstruation. The external genital 
organs become swollen and a discharge of mucus takes 
place from the uterus. The mucous membrane of the 
canine uterus undergoes histological changes similar to 
those of menstruation; that is, the membrane increases 
in size, becomes congested with blood, and exhibits a 
phase of degeneration during which some of the epithelial 
lining may be cast off and some hemorrhage occur. As 
in the case of the menstrual period, the heat period or 
oestrum cycle may be divided into four subperiods (Mar- 
shall and Jolly): the prooestrum, during which the 
genital organs are congested and swollen, corresponds CELLULAR BASIS OF SEX DETERMINATION. 
175 
with menstruation; the oestrum, the period of sexual 
desire; the metoestrum, the period of repair and return 
to normal conditions, and the anoestrum, the period of 
rest. The prooestrum is caused by the active develop- 
ment of one or several Graafian follicles to maturity, 
producing congestion of the ovaries. When the Graafian 
follicle has advanced to, and protrudes from, the surface 
of the ovary the pressure in the organ is to a great extent 
relieved, then the more active congestion subsides. This 
condition may last from three to nine days, but in some 
dogs it is not so marked as to be noticeable. As the 
active congestion of the ovaries subsides it is superseded 
by oestrum, the period of sexual desire, when the female 
will admit the male. This period lasts until all the 
Graafian follicles are ruptured, which is from one to 
fifteen days. If the hymen or vagina is lacerated by the 
bulbus glandis of the male during coitus, which is often 
the case in both nulliparous and multiparous dogs, or 
when all the Graafian follicles are ruptured, the female 
will not admit the male. This period is followed by 
metoestrum, repair of the ovaries in the immediate 
section of the ruptured Graafian follicles, when the 
swelling and congestion of the vulva and vagina subside; 
then anoestrum, the period of rest, is established. 
Fertilization of the ovum in the dog family does not 
take place until rupture of the Graafian follicle occurs; 
then, if the ovum has not been extruded from the follicle, 
it may be fertilized while still in the ovary, or else in the 
ovarian bursa, in either horn of the uterus, or in the 
uterus. 
Rupture of the Graafian follicle usually takes place 
between the fifth and fourteenth days of the oestrum 176 
THE CELLULAR DETERMINATION OF SEX. 
period, though it may take place at any time during this 
period. 
To produce all females in the dog: Allow one sexual 
connection the first day the female will admit the male; 
then protect the female from all dogs, feed lightly for 
five days, using very little if any meat, keep her in a 
comfortable place for sixteen days, after that give her 
her liberty, and she will produce six females to one male. 
This result is caused by the spermatozoa being partly 
aged in the male generative organs, and by their waiting 
for the rupture of the Graafian follicles in the female 
before they can fertilize the ovum. The fact that the 
male dog has had but one sexual intercourse has prevent- 
ed the presence of young spermatozoa in the semen, 
since that first ejected is always more or less aged. By 
feeding the female lightly engorgement of the intestinal 
canal is prevented, and the blood-vessels contain less of 
highly nutritious blood, both of which conditions would 
go far toward augmenting the rupture of the Graafian 
follicles. Now to reverse the conditions and produce 
males: As soon as the female dog shows that she will 
take the male, see that sexual union is prevented for ten 
days, then use a male that has had sexual union three or 
four times the day previous with some other female dog; 
this will insure all male offspring. In this case the 
spermatozoa are young when they leave the male dog 
and enter the female generative organs; they do not wait 
long, if at all, for the rupture of the Graafian follicles; 
fertilization of the ovum takes place immediately or very 
soon after copulation. In this case there are not so 
many pups produced, as some of the ova will have 
passed out before the sexual union. The following is CELLULAR BASIS OF SEX DETERMINATION. 
177 
the result of experiments along this line, conducted 
by myself:- 
No. i. One female spaniel dog, belonging to one Mr. 
H., a merchant, went in heat, and sexual union was 
prevented for ten to twelve days; littered only two male 
pups. 
No. 2. One female black mongrel dog, weight 35 lbs., 
aged 3 years, lean and poorly fed, in which oestrum 
began on March 29th, 1910; sexual union was prevented 
until 9 o'clock P.M., April 11, 1910. On June 9, 1910, 
she gave birth to two male pups. 
No. 3. One female yellow mongrel dog, weight 28 lbs., 
very lean and poorly fed, aged 4 years; oestrum began 
on April 7th, 1910, sexual union following on night of 
the same day. In this case the hymen and vulva were 
badly lacerated by the bulbus glandis of the male. All 
swelling about the vulva passed away on April 22d, 1910, 
when she would not take the male. On June 8th, 1910, 
she gave birth to one male and six female pups. 
No. 4. One female black bird dog, weight 36 lbs., aged 
3 years, lean and poorly fed. CEstrum began on April 
12th, 1910; sexual union was prevented for nine days, 
when all swelling about the vulva had passed away, then 
she would not allow a dog to touch her. 
No. 5. One female white bulldog, weight 45 lbs., in 
fair condition and very well fed, aged 5 years. Gave 
birth to two male and four female pups on June 5th, 1910. 
Three of the pups were dead at birth and all the rest 
died in a few days, cause unknown. Here the female 
dog failed to show any sign of oestrum and went unob- 
served by a very watchful keeper. 
No. 6. One female sheep dog, weight 38 lbs., in good 178 
THE CELLULAR DETERMINATION OF SEX. 
condition, and well fed during oestrum. (Estrum began 
on June 3d, 1910, copulation took place on the following 
day. In this case the male was 18 months old, and it is 
probable that he had been with some other female dog 
the day previous. In August the bitch gave birth to 
two female and three male pups. The result in this case 
is apparently reversed, but when we consider the youth 
of the spermatozoa from the male and the fact that the 
female had been much better fed during oestrum than 
she was in a habit of being, it is about what one might 
anticipate. The same female dog went in oestrum in 
February, 1911, cohabitation followed on the second or 
third day of oestrum, and she littered six female pups in 
April. 
No. 7. One small female yellow mongrel dog, weight 
23 lbs., aged 4 years, lean, poorly fed. CEstrum began 
August 16th, 1910; sexual union was prevented until 
August 23d; on October 23d she gave birth to one female 
and three male pups. 
In the Human Family.-In taking up this problem as 
applying to the human family, the results are much more 
convincing and satisfactory. When the human being 
can see how well and truly this law is fulfilled in his own 
family, its operation is more convincing than any or all 
the results one might obtain in the animal kingdom by 
experimenting for the next century. For this reason the 
following work has been done in the human family. The 
human species is not unlike many insects, birds, and 
mammals, many of which have their period for court- 
ship, though they do not reach the superlative degree as 
seen in man. In the animal kingdom, insemination takes 
place at the conclusion of a successful courtship, without CELLULAR BASIS OF SEX DETERMINATION. 
179 
the formalities of legal sanction and the ministerial 
benediction; but this is not the case in the human family, 
for very many reasons. The generative organs of a 
woman are so different from those of insects, birds, and 
very many mammals, that it becomes necessary for her 
to consult a calendar before she is able to name a date 
for the happy nuptials, which date must not be too close 
to the menstruation before marriage, nor too near the 
menstruation which succeeds the honeymoon. It must 
be made to fall on a Wednesday, and not on a Wednesday 
coming on the thirteenth of the month. The thirteenth 
is considered an unlucky date and is avoided for that 
reason. If the date for marriage is set near the ending 
of menstruation, it might be delayed from some cause 
and run into the marriage date. Again, if the date is 
made very late after menstruation, the succeeding 
menstruation is liable to be hastened and come on six or 
eight days prematurely, owing to the excitement incident 
to marriage. The date must come on a Wednesday, for 
such is the custom. Though there are many conditions 
and circumstances to be considered, those designated 
above are the predominating factors in setting the date 
for marriage. There are very few if any women whose 
menstruation is absolutely regular. It will vary from 
two to five days or longer. The flow may continue for 
about the same number of days, but the duration will 
vary in different women, and in the same woman at 
different times. For this reason it is necessary to set the 
date for marriage as near as possible midway between the 
cessation of one menstrual flow and the beginning of the 
anticipated menstruation, varying a few days to have it 
on a convenient day or date. The dates for marriage 180 
THE CELLULAR DETERMINATION OF SEX. 
given in the following calendar follow the cessation of the 
menstrual flow as near as they could be set with safety; 
for the arrangement is usually made two months prior to 
marriage, and they could not be set a week later, for fear 
they would run into the first menstruation after marriage. 
CALENDAR, 1911 
Sun. 
Mon. 
Tues. 
Wed. 
Thurs. 
Fri. 
Sat. 
I 
2 
3 
4 Men. begins 
5 
6 
7 Men. ceases 
8 
9 
IO 
11 
12 
13 
14 
15 
16 
17 
18 Marriage 
19 
20 
21 
22 
29 
23 
30 
24 
31 
25 
26 
27 
28 
JANUARY 
5 
6 
7 
i Men. begins 
8 
2 
9 
3 
10 
4 Men. ceases 
11 
12 
13 
14 
15 Marriage 
16 
17 
18 
19 
20 
21 
22 
23 
24 
25 
26 
27 
28 
FEBRUARY 
MARCH 
5 
6 
7 
I Men. begins 
8 
2 
9 
3 
10 
4 Men. ceases 
11 
12 
13 
i4 
15 Marriage 
16 
17 
18 
19 
20 
21 
22 
23 
24 
25 
26 
27 
28 
29 Men. begins 
30 
31 
APRIL 
2 
3 
4 
5 
6 
7 
1 
8 
Men. ceases 
9 
10 
11 
12 Marriage 
13 
14 
15 
i6 
17 
18 
19 
20 
21 
22 
23 
30 
24 
25 
26 Men. begins 
27 
28 
29 
Men. ceases CELLULAR BASIS OF SEX DETERMINATION. 
181 
CALENDAR, 1911.-Continued 
MAY 
Sun. 
Mon. 
Tues.. 
Wed. 
Fri. 
Thurs. 
Sat. 
I 
2 
3 
4 
5 
6 
7 
8 
9 
10 Marriage 
II 
12 
13 
14 
15 
16 
17 
18 
19 
20 
21 
22 
23 
24 Men. begins 
25 
26 
27 Men. ceases 
28 
29 
30 
3i 
JUNE 
4 
5 
6 
7 Marriage 
1 
8 
2 
9 
3 
10 
ii 
12 
13 
14 
15 
16 
17 
i8 
19 
20 
21 Men. begins 
22 
23 
24 Men. ceases 
25 
26 
27 
28 
29 
30 
JULY 
2 
3 
4 
5 Marriage 
6 
7 
1 
8 
9 
10 
11 
12 
13 
14 
15 
i6 
17 
18 
19 Men. begins 
20 
21 
22 Men. cer ses 
23 
30 
24 
3i 
25 
26 
27 
28 
29 
AUGUST 
6 
7 
I 
8 
2 Marriage 
9 
3 
10 
4 
11 
5 
12 
13 
14 
15 
16 Men. begins 
17 
18 
19 Men. ceases 
20 
27 
21 
28 
22 
29 
23 
30 Marriage 
24 
31 
25 
26 182 
THE CELLULAR DETERMINATION OF SEX, 
CALENDAR, 1911.-Continued 
SEPTEMBER 
Sun. 
Mon. 
Tues. 
Wed. 
Thurs. 
Fri. 
Sat. 
I 
2 
3 
4 
5 
6 
7 
8 
9 
IO 
11 
12 
13 Men. begins 
14 
15 
16 Men. ceases 
17 
18 
19 
20 
21 
22 
23 
24 
25 
26 
27 Marriage 
28 
29 
30 
OCTOBER 
I 
8 
9 
3 
10 
4 
11 Men. begins 
5 
12 
6 
13 
7 
14 Men. ceases 
15 
16 
17 
18 
19 
20 
21 
22 
29 
23 
30 
24 
3i 
25 Marriage 
26 
27 
28 
5 
6 
7 
I 
8 Men. begins 
2 
9 
3 
10 
4 
11 Men. ceases 
12 
13 
14 
15 
16 
17 
18 
19 
26 
20 
27 
21 
28 
22 Marriage 
29 
23 
30 
24 
25 
NOVEMBER 
DECEMBER 
3 
4 
5 
6 Men. begins 
7 
I 
8 
2 
9 Men. ceases 
10 
ii 
12 
13 
14 
15 
16 
17 
i8 
19 
20 Marriage 
21 
22 
23 
24 
3i 
25 
26 
27 
28 
29 
30 
In the above cases, insemination would usually follow 
on the twelfth day after the cessation of menstruation. CELLULAR BASIS OF SEX DETERMINATION. 
183 
If the cessation of menstruation had come on Wednesday, 
Thursday, or Friday, instead of Saturday, insemination 
would not have followed until the fifteenth, fourteenth, 
and thirteenth day, respectively, after menstruation. 
After the sixteenth day, it is too late in most cases to 
produce pregnancy. If the date of marriage were 
changed and made a week earlier, when the cessation of 
menstruation followed on Tuesday, Wednesday, Thurs- 
day, and Friday, instead of Saturday, a female child 
would be produced, for insemination following seven days 
after menstruation will almost always produce a female; 
if still nearer the period, a female is sure to be produced. 
Now at least we can understand why insemination does 
not follow very soon after the menstruation before 
marriage. If this were the case the number of children 
produced during the honeymoon should be overwhelm- 
ingly male; while those produced immediately after the 
first menstruation following marriage should be over- 
whelmingly female. If there ever is a time during the 
matrimonial career at which insemination takes place 
soon after the cessation of menstruation, it is that follow- 
ing the first menstruation. 
Below is given the result of one thousand marriages; 
the records in two-thirds of the cases were taken directly 
from the family Bible, and most of them are absolutely 
correct. The fact that 157 children are born nine months 
after marriage to 983 women, and that 189 children are 
born ten months after marriage to 826 women perma- 
nently establishes the point that only 7 per cent more 
pregnancies follow early insemination after cessation of 
menstruation. 184 
THE CELLULAR DETERMINATION OF SEX. 
First Pregnancy after Marriage of 1,000 Women. 
Boys. 
Girls. 
Total. 
Per cent of 
Pregnancies 
8th month 
5 
12 
17 
i .6 
9th " 
129 
28 
157 
15-7 
10th " 
53 
136 
189 
22.7 
nth " 
63 
35 
98 
I5-I 
12th " 
46 
30 
76 
13-5 
I3th " 
27 
33 
60 
12.2 
14th " 
30 
36 
66 
16.0 
I5th " 
14 
13 
27 
7.8 
16th " 
16 
11 
27 
8-5 
17th " and later 
160 
131 
291 
100.0 
Total births 
543 
465 
1,008 
Number of Children Born to 1,000 Women. 
Pregnancies. 
Boys. 
Girls. 
Total. 
1st 
543 
465 
1,008 
2d 
425 
444 
869 
3d 
360 
347 
707 
4th 
285 
275 
560 
5th 
220 
212 
432 
6th 
174 
160 
334 
7th 
119 
120 
239 
8th 
89 
92 
l8l 
9th 
75 
58 
133 
10th 
41 
28 
69 
nth 
21 
20 
41 
12th 
14 
15 
29 
13th 
7 
9 
16 
14th 
2 
8 
IO 
15th 
2 
5 
7 
16th 
2 
1 
3 
Total 
2,379 
2,259 
4,638 CELLULAR BASIS OF SEX DETERMINATION. 
185 
Labor. 
Both Boys. 
Both Girls. 
Girl and 
Boy. 
Total. 
1st 
3 
3 
2 
8 
2d 
2 
2 
4 
8 
3d 
1 
2 
2 
5 
4th 
1 
O 
1 
2 
5th 
I 
3 
1 
5 
6th 
2 
1 
0 
3 
8th 
I 
1 
9th 
1 
2 
3 
12th 
I 
1 
14th 
1 
1 
I5th 
1 
1 
Total No. of labors.. . . 
13 
12 
13 
38 
Total No. of children ... 
26 
24 
26 
76 
Number of Twins Born in 4,600 Labors. 
Occupations of the Men. 
Farmers 370 
Carpenters 143 
Miners 77 
Merchants 102 
Physicians 30 
Barristers 12 
Ministers 19 
Dental surgeons 13 
Hotel proprietors 9 
Millers 8 
Bakers 3 
Lumbermen 21 
Teachers 42 
Financiers 25 
Salesmen 39 
Railroad conductors 78 
Powder makers 9 
Total 1,000 
The following table gives the age, weight, and height 
of fifty-three men and women who produced male chil- 
dren ten months after marriage. 
Men. 
Women. 
Age. 
Weight. 
Height. 
Age. 
Weight. 
Height. 
18 
160 
5' IO" 
14 
136 
5' 6" 
30 
152 
5' 8" 
22 
132 
5' 
23 
146 
6' 
23 
126 
5' 5" 
53 
167 
5' 8" 
17 
155 
5' 4" 
30 
131 
6' 
30 
Il6 
5' 6" 
19 
150 
5' 8" 
23 
125 
5' 3" 
22 
150 
5' 10" 
19 
120 
5' 5" 186 
THE CELLULAR DETERMINATION OF SEX. 
Men. 
Women. 
Age. 
Weight. 
Height. 
Age. 
Weight. 
Height. 
23 
160 
5' 8" 
18 
140 
5' 7" 
21 
178 
6 
28 
160 
5' 4" 
23 
150 
5' u" 
21 
115 
5' 3" 
24 
170 
6' 2" 
23 
116 
5' 2" 
26 
148 
6' 
28 
184 
5' 6" 
24 
180 
5' 9" 
120 
5' 2" 
24 
180 
6' 1" 
24 
130 
5' 4" 
26 
167 
6' 2" 
16 
106 
5' 3" 
29 
152 
6' 
24 
120 
5' 4" 
23 
150 
5' 10" 
21 
130 
5' 5" 
22 
156 
5' 10" 
29 
110 
5' 6" 
25 
156 
5' 11" 
23 
155 
5' 6" 
26 
150 
6' 
19 
125 
5' 6" 
24 
125 
5' 10" 
21 
140 
5' 5" 
23 
120 
5' 6" 
l6 
140 
5' 4" 
23 
140 
5' 4" 
18 
140 
5' 8" 
26 
163 
5' 10" 
23 
135 
5' 5" 
23 
145 
6' 
18 
120 
5' 6" 
24 
140 
5' 6" 
28 
I40 
5' 3" 
32 
140 
6' 
21 
116 
5' 4" 
25 
172 
5' 8" 
17 
122 
5' 4" 
21 
170 
5' 10" 
21 
150 
5' 5" 
25 
170 
5' 11" 
20 
150 
5' 4" 
44 
165 
5' 10" 
20 
I40 
5' 4" 
29 
126 
5' 9" 
19 
90 
5' 
23 
130 
5' 6" 
23 
IIO 
5' 
25 
176 
5' 11" 
24 
170 
5' 8" 
23 
130 
5' 6" 
18 
130 
5' 7" 
16 
170 
6' 2" 
17 
118 
5' 
22 
150 
6' 
21 
125 
5' 6" 
26 
165 
5' 
21 
108 
5' 4" 
29 
157 
5' 10" 
23 
106 
5' 4" 
60 
160 
6' 
18 
128 
5' 6" 
24 
160 
5' 10" 
22 
116 
5' 4" 
30 
155 
5' 9" 
26 
125 
5' 3 
25 
165 
5' 9" 
21 
125 
5' 4" 
32 
150 
5' 7" 
17 
128 
5' 7" 
52 
173 
6' 
31 
95 
5' 5" 
22 
150 
5' 11" 
24 
115 
5' 
36 
170 
5' 9" 
21 
IIO 
5' 9" 
28 
130 
5' 6" 
21 
115 
5' 6" 
22 
145 
5' 9" 
23 
115 
5' 4" 
21 
130 
5' 5" 
19 
120 
5' 4" 
27 
150 
5' 7" 
26 
106 
5' 2" 
21 
150 
5' 10" 
17 
125 
5' 4" 
29 
130 
5' 9" 
26 
150 
5' 4" 
Aver. 27 
152 
5' 9" 
Aver. 22 
127 
5' 4" CELLULAR BASIS OF SEX DETERMINATION. 
187 
The following are those who produced female children 
nine months after marriage. 
Husband. 
Wife. 
Age. 
Weight. 
Height. 
Age. 
Weight. 
Height. 
42 
180 
5' II" 
22 
105 
5' 3" 
24 
140 
5' 9" 
21 
130 
5' 6" 
24 
136 
5' 
20 
I40 
5' 7" 
29 
150 
5' 8" 
24 
122 
5' 2" 
20 
148 
5^ 4" 
19 
I40 
5' 4 
42 
165 
5' 8 
17 
130 
5' 3" 
24 
175 
5' 10" 
23 
150 
5' 5" 
29 
150 
6 
41 
125 
5' 11" 
19 
185 
5' 10" 
17 
120 
5' 4" 
24 
160 
6' 
19 
150 
5' 5" 
23 
140 
5' 8" 
21 
115 
5' 2" 
21 
148 
5' 8" 
22 
129 
5' 9" 
37 
140 
5' 6" 
21 
IIO 
5' 
28 
130 
5' 5" 
20 
IIO 
5' 5" 
20 
150 
6' 
23 
140 
5' 4" 
26 
150 
6' 
25 
130 
5' 2" 
22 
135 
5' 11" 
27 
135 
5' 8" 
27 
175 
5' 10" 
21 
130 
5' 6" 
30 
155 
5' 8" 
19 
135 
5' 5 
33 
150 
6' 
24 
135 
5' 4" 
21 
I44 
5' 10" 
25 
144 
5' 6" 
23 
148 
5' 9" 
21 
125 
5' 8" 
28 
135 
5' 8" 
35 
100 
5' 4 
25 
145 
5' 9" 
17 
95 
5' 
22 
140 
5' 6" 
18 
110 
5' 
30 
170 
6' 
18 
120 
5' 5" 
19 
178 
5' 10" 
22 
160 
5' 4" 
30 
148 
5' 7" 
21 
130 
5' 4" 
Aver. 27 
152 
5' 9" 
Aver. 22 
127 
5' 4" 
Total. 
. 28 
Of the one hundred and fifty-seven children produced 
nine months after marriage, only twenty-eight are female; 
twenty of these are in cases in which the father or mother, 
or both, were twenty-four years old or older (see Second- 
ary laws, age and occupation). This leaves eight cases, 188 
THE CELLULAR DETERMINATION OF SEX. 
six of which were in hard-working farmers' daughters, in 
a class of people who would not be likely to give menstru- 
ation the serious consideration that others would, in 
setting the date for marriage. Two of them were of a 
class that would use the best judgment and discretion 
in setting a date for marriage, and they might be sup- 
posed to have set the day soon after the cessation of 
menstruation. The occupations of the husbands are: 
fifteen farmers, four merchants, three civil engineers, one 
miller, one baker, one laborer, one druggist, one teacher, 
and one physician. 
Of the one hundred and eighty-nine children born to 
the remaining eight hundred and twenty-six women, 
fifty-three are male, and one hundred and thirty-six are 
female. It may cause some surprise that there are so 
many boys resulting from these inseminations early after 
the cessation of menstruation; but when we consider 
that, in some at least, the insemination does not occur 
soon, and that in others the young male-producing 
spermatozoa are kept present by repeated inseminations, 
then the result is just what might have been anticipated. 
If insemination had stopped on the sixth day after the 
cessation of menstruation, there would have been at least 
forty boys less. The production of a girl can never be 
made quite so certain as that of a boy, for the reason that 
the male-producing spermatozoa move faster and keep 
in advance of the female-producing ones, and if the ovum 
has been extruded from the ovary at the time of insem- 
ination, the male-producing spermatozoa are sure to 
reach the ovum first. In both of these categories- 
where the male was produced where the female should 
have been, and the female produced where the male CELLULAR BASIS OF SEX DETERMINATION. 
189 
should have been-the average age, weight, and height 
are the same, but the significant fact is that the weight 
of the men is less than the average of the i ,000, which is 
155 lbs. The occupations of the husbands are: twenty - 
four farmers, four merchants, four carpenters, two black- 
smiths, two bakers, two miners, two millers, two sales- 
men, two civil engineers, one physician, one minister, 
one coal-operator, one insurance solicitor, one railroad 
cashier, one stenographer, one United States deputy 
marshal, one station agent, and one whisky manufac- 
turer. (See Table of Occupations, p. 185.) 
Among the thousand women on record, eighty-two 
did not produce children until between two and three 
years after marriage; forty-one between three and four 
years; seven between four and five years; six between 
five and six year ; three between six and seven years; 
one between nine and ten years, and only one in the 
tenth year, after which period all were as prolific as those 
who conceived early after marriage. 
Among the seventy-six twins produced in four thou- 
sand six hundred labors, there were thirteen cases in 
which both were males, both females in twelve, and in 
thirteen, one male and one female, which proportion 
shows a most beautiful rounding up of results by nature, 
and also that the statistical ratio of males to females is 
maintained. 
The first record in history of anything having been 
done for the prevention of sterility appears in the 
marriage of Abram and Sarai (Gen. xi. 29-30). After 
many years of married life Abram lamenting said, Lord 
God, what wilt thou give me, seeing I go childless, and 
the steward of my house is this Eliezer of Damascus? 190 
THE CELLULAR DETERMINATION OF SEX. 
And Abram said, Behold, to me thou hast given no seed 
(Gen. xv. 2, 3). And when Abram was ninety years old 
and nine, the Lord appeared to Abram, and said unto 
him, I am the Almighty God; walk before me, and be 
thou perfect. And I will make my covenant between 
me and thee, and will multiply thee exceedingly. This 
is my covenant, which ye shall keep, between me and 
you and thy seed after thee: Every man child among 
you shall be circumcised. And ye shall circumcise the 
flesh of your foreskin; and it shall be a token of the 
covenant betwixt me and you. And he that is eight 
days old shall be circumcised among you, every man 
child in your generations, he that is born in the house or 
bought with money of any stranger, which is not of thy 
seed. In the selfsame day was Abraham circumcised, 
and Ishmael his son. And all the men of his house, born 
in the house, and bought with money of the stranger, 
were circumcised with him (Gen. xvii. 1-2, 10-12, 26, 
27). 
In this case we see the beginning of circumcision, the 
result of which is a son born to a man in his ninety-ninth 
year, from a childless woman in her ninetieth year, and 
six sons from the second wife. Ishmael, who was cir- 
cumcised at the same time with his father Abraham, 
produced twelve male children. Abraham's six sons 
from Keturah were: Zambran, Jazar, Madan, Madian, 
Josabak, and Sous. The sons of Sous were: Sabathan 
and Dadan; the sons of Dadan were Latusim, and Assur, 
and Luom; the sons of Madian were Ephas, and Ophren, 
and Anoch, and Ebidas, and Eldas. The sons of Isaac 
were Esau and Jacob. Esau had five legitimate and 
one illegitimate sons. The daughters are not mentioned, CELLULAR BASIS OF SEX DETERMINATION 
191 
and the daughter of Ishmael is only incidentally given in 
Esau's marriage to her. The sons of Jacob (or Israel) 
were many. All the souls that came with Jacob into 
Egypt, which came out of his loins, besides Jacob's sons' 
wives, all the souls were threescore and six (Gen. xlvi. 
26). The number of female children from Jacob were 
only two to this time: his daughter Dinah, by Lea; and 
his granddaughter, Sarah, by Asher. And the children 
of Israel were fruitful, and increased abundantly, and 
multiplied, and waxed exceedingly mighty; and the land 
was filled with them. So great were the number of males 
born to the Israelites that the new king over Egypt, 
which knew not Joseph, gave the following instructions: 
" And the king of Egypt spake to the Hebrew midwives, 
of which the name of one was Shiphrah, and the name of 
the other Puah; and he said, When ye do the office of a 
midwife to the Hebrew women, and see them upon the 
stools; if it be a son, then ye shall kill him; but if it 
be a daughter, then she shall live." Failing in this, the 
Pharaoh charged all his people, saying, " Every son that 
is born ye shall cast into the river, and every daughter 
ye shall save alive " (Ex. i. 7, 8, 15, 16, and 22). This 
injunction had not been given until about sixty years 
after the death of Joseph, which was about the time of 
the birth of Moses, who in his eightieth year conducted 
his nation safely out of the land of Egypt. The entire 
multitude of those that went out, including the women 
and children, was not easy to be numbered; but those 
that were of an age fit for war, were six hundred thousand. 
Now, all these were the offspring of Jacob, who had 
removed into Egypt two hundred and fifteen years be- 
fore. That there was a great excess of males is shown 192 
THE CELLULAR DETERMINATION OF SEX. 
by the Midianites who sent their daughters near to the 
Israelite camp, that many of them might be taken for 
wives by the soldiers who would later accept the Midian- 
ite god for their own; so successful was this scheme 
that it became necessary for Moses to destroy twenty- 
four thousand of his own soldiers, to prevent further 
sedition, which never would have occurred had there 
been an equal number of females in the Israelite nation. 
Moses had one brother and one sister, and produced only 
two sons. Aaron, a brother of Moses, had four children, 
all of whom were male. Gideon had seventy sons by 
many wives; history fails to mention any daughters. 
Jair had thirty sons; if he had daughters, history fails 
to mention them. Eli had two sons. Saul, the first 
king of Israel, had three sons and two daughters. King 
David had eleven sons and one daughter, Tamar, a full 
sister of Absalom. Solomon had seven hundred wives 
and three hundred concubines, and produced only one 
son, Rehoboam; and this man produced only one son, 
Abijah. Abijah produced twenty-two sons and sixteen 
daughters by fourteen wives. Asa, a son of Abijah, be- 
came king of Jersualem, and was succeeded by his only 
child and son, Jehoshaphat. Jehoshaphat is credited 
with the production of but one son, Jehoram, who suc- 
ceeded him as king. These were the most virtuous, high, 
and easy-living families of the Jewish race, for a period 
of more than eleven hundred years. When any children 
were produced, they never failed to produce a male to 
succeed them. The preponderance of males in this race 
of people is beyond anything I had anticipated. This 
condition has been noted before by Mr. Charles Darwin 
who gives the following data: " It is a singular fact that CELLULAR BASIS OF SEX DETERMINATION. 
193 
with Jews the proportion of male births is decidedly 
larger than with Christians; thus in Prussia the propor- 
tion is as one hundred and thirteen, in Breslau as one 
hundred and fourteen, and in Livonia as one hundred 
and twenty to one hundred; the Christian births in these 
countries being the same as usual; for instance, in 
Livonia as one hundred and four male to one hundred 
female." 
The predominance of male-production in the Jewish 
nation is due to two conditions, either of which is capable 
of producing this result, but when both act together a 
male is almost sure to be produced. 
These two conditions are: 
1st. Circumcision of the male. 
2d. The observance of the Levitical law by the female: 
in this she is instructed to wait seven days after the last 
day of the menstrual flow before allowing insemination. 
1st. In case of circumcision of the male, the prepuce is 
removed, and the glans penis is left bare. In this con- 
dition it becomes less sensitive and tender to the touch, 
on account of its being continually dry and coming in 
contact and rubbing against the rough clothing the Jews 
usually wear. For this reason the seminal fluid is not 
ejected so early during the sexual act and the female is 
more liable to be brought to orgasm, which usually 
causes rupture of a Graafian follicle, and which may- 
be produced from six to twelve days after cessation of 
the menstrual flow. 
2d. The female having waited until the seventh day 
after the menstrual flow, the Graafian follicle is now 
about ready to rupture. In many cases it may be 
ruptured at the point of orgasm during cohabitation on 194 
THE CELLULAR DETERMINATION OF SEX. 
the seventh day after the menstrual flow; in which 
event the production of a male is almost inevitable. 
These are the secrets of the great vitality of the Jewish 
nation for the past three thousand eight hundred and 
thirty years. By this method of child-production, the 
young active spermatozoa fertilize the well-matured 
ovum in its most vigorous state, with the result of pro- 
ducing the strongest child possible, one that is ever quick 
to think and act, and that possesses great power and 
stamina for immediate and continued exertion. All 
success through life depends upon these qualities, both 
individually and collectively. 
Mr. Charles Darwin says: " It seems at first sight a 
mysterious fact that in different nations, under different 
conditions and climates, in Naples, Prussia, Westphalia, 
Holland, France, England, and the United States, the 
excess of male over female births is less when they are 
illegitimate than when legitimate." His explanation 
for this follows: " This has been explained by different 
writers in many different ways, as from the mothers 
being generally young, from the large proportion of first 
pregnancies, etc. But we have seen that male infants, 
from the large size of their heads, suffer more than female 
infants during parturition; and as the mothers of illegiti- 
mate children must be more liable than other women to 
undergo bad labors, from various causes, such as attempts 
at concealment by tight lacing, hard work, distress of the 
mind, etc., their male infants would proportionately 
suffer. And this probably is the most efficient of all the 
causes of the proportion of the males to females born 
alive being less among illegitimate children than among 
the legitimate." This to me does not touch the true CELLULAR BASIS OF SEX DETERMINATION. 
195 
cause, which is given in the following: The male does 
not seek the harlot until the vesiculae seminales are filled 
and distended with aged spermatozoa of many days' 
accumulation, and the harlot does not wait any settled 
length of time after the cessation of the menstrual flow 
before she allows insemination, but coition usually begins 
when the flow ends, in which case the Graafian follicle 
is not ruptured during the act, nor can it be for several 
days after the cessation of the menstrual flow; and dur- 
ing this time the Fallopian tubes are filled with aged 
female-producing spermatozoa. Female-production is 
further favored by the engorgement of the vesiculae 
seminales with aged spermatozoa, which are ejected early 
during the sexual act, before the female has reached 
orgasm or received any shock, which is so necessary to 
rupture the Graafian follicle in male-production. The 
same condition prevails in the case of a heavy fat man, 
whose energy is consumed in locomotion with a conse- 
quent disinclination for cohabitation. He allows his 
vesiculae seminales to become engorged with spermatozoa 
for many days, until most of them are dead, many are 
female-producing, and a very few are male-producing. 
During the sexual act they are ejected almost immediate- 
ly upon the entrance of the penis into the vagina, before 
the female has reached orgasm or received any shock. 
The same explanation applies to the chaste man, to the 
weak debilitated man, and to men who are sexually in- 
active from any cause; all of whom are prone to female- 
production. In case the female remains in an apathetic 
condition during cohabitation, she feels no orgasm or 
shock, which is necessary to produce rupture of the 
Graafian follicle, as above stated. The apathetic con- 196 
THE CELLULAR DETERMINATION OF SEX. 
dition on the part of the female may be caused by the 
chaste life she has lived before; by her total ignorance of 
the sexual union; and by her lack of affection for her 
husband. Moreover, a weakened or debilitated con- 
dition of the female from any cause will go far toward 
producing female offspring. 
After the thirty years' war in Germany, so many men 
had perished in battle, by disease, and by bad conditions 
incident to long wars, that there were two women for 
every man. For that reason some of the provinces re- 
laxed their marriage laws and allowed a man to take two 
wives. The balance of the sexes, it is stated, at once 
began to restore itself, and before the end of the century 
the normal equilibrium had been reestablished. The 
wives under such conditions are more liable to late in- 
semination after the menstrual flow, and by copulating 
less frequently, they are more passionate and susceptible 
to the sexual shock and orgasm which serve so well to 
rupture the Graafian follicle when it is well matured. 
On the other hand, the vesiculae seminales of the hus- 
bands are kept free from an accumulation of old sperma- 
tozoa which are female-producing. The spermatozoa are 
produced very slowly in a hard-working man, and hence 
there is more room for the larger growth of the nuclei 
which thus acquire the male-producing quality. Be- 
sides, a small quantity of semen is not ejected so soon 
during sexual intercourse, and the prolongation of the 
act aids in bringing the female to orgasm, with the result 
above explained. Thus all conditions contribute to the 
production of males. 
Punnett has given the official census of the county of 
London, 1901: "The metropolis is divided into 29 bor- CELLULAR BASIS OF SEX DETERMINATION. 
197 
oughs. Exclusive of the city of London, with its peculiar 
conditions, we are left with 28 boroughs, having a total 
population of just over 4,500,000. For each of these 
boroughs the proportion of male to female infants under 
one year has been reckoned. The servant-keeping ca- 
pacity has been taken as the guide to the relative wealth 
of the different boroughs, it being assumed that when a 
family is able to do so it will keep a servant. In table I 
the 28 boroughs are arranged in order of wealth (on the 
servant-keeping capacity basis), while at the same time 
the relative proportion of male and female infants is 
given. The 28 boroughs have been arranged in three 
groups: A, with a percentage of indoor servants less 
than 15 (100 families); B, with a percentage of over 15 
but less than 30; and C, with a percentage of over 30. 
The relative proportion of male and female infants then 
works out to:- 
99.5 males per 100 females: for group A. 
100.7 males per 100 females: for group B. 
102.2 males per 100 females: for group C. 
A 
B 
C 
Male 
20,309 
23,327 
11,038. 
Female 
20,413 
23J59 
10,841. 
"While in a table of 5,225 children in Burke's Peerage 
this condition is accentuated by a still greater increase of 
the male, as 107.6 males to 100 females." The operating 
factors here are probably in both father and mother. 
Those women who have both the quality and quantity 
of food desired will mature a Graafian follicle sooner after 
menstruation than those who are deprived of the quality 
and in this case probably some are deprived of the quan- 198 
THE CELLULAR DETERMINATION OF SEX. 
tity of food desired. The better classes are more liable 
to defer the sexual union after menstruation than the 
poor. The vesiculae seminales of the better classes are 
more liable to be drained of the aged female-producing 
spermatozoa. Both of the above conditions tend very 
materially to the production of males. 
Case i.-A vigorous man, aged 23, weight 140 lbs., 
who had spermatorrhoea, married a woman, aged 26, 
weight 98 lbs. A male child was born to them nine 
months later. After that three daughters were born to 
them, the first about three years after the boy in 1874, 
a second daughter in 1876, and a third daughter in 1878. 
In this case the first insemination did not take place until 
the twelfth day after the menstrual flow, at which time 
the Graafian follicle ruptures in most cases from the 
slightest cause. On account of the spermatorrhoea, the 
production of females followed later insemination. This 
case shows us that, without the shock of orgasm, we can 
produce a male by inseminating at the proper time, and 
that female-production inevitably results from early 
insemination unaccompanied by the shock of orgasm on 
the part of the female. 
Case 2.-A man, aged 43, weight 165 lbs., married a 
woman aged 28, weight 135 lbs., waited until fourteen 
days after the last day of the menstrual flow to prevent 
the production of children. This was followed by a fine 
son in fourteen months after marriage and a second son 
three years later. 
Case 3.-A man, aged 24, weight 120 lbs., married a 
woman aged 20, weight 140 lbs., had a run of three daugh- 
ters in succession and to prevent the further production 
of children did not copulate until twelve days after the CELLULAR BASIS OF SEX DETERMINATION. 
199 
menstrual flow. This was followed by the production 
of four sons in succession. 
Case 4.-A man, aged 36, weight 125 lbs., married a 
woman aged 19, weight 135 lbs., produced three daugh- 
ters in succession, and to prevent the production of more 
children deferred insemination until twelve days after 
the last day of the menstrual flow, and this was followed 
by the production of a son. 
Case 5.-A man, aged 23, weight 160 lbs., married a 
woman, aged 20, weight 165 lbs., produced two daughters 
in succession; at this time she was informed by one of 
her friends that she could produce boys by waiting nine 
days after the menstrual flow before insemination. She 
followed this advice and produced five sons in succession. CHAPTER IX. 
SECONDARY LAWS. 
Maternal Secondary Laws.-The secondary conditions 
in the mother and father which go to determine the pro- 
duction of sex are many, any of which may be placed 
under one of the following divisions of the Maternal 
Secondary Laws:- 
(i) Physical condition of the ovary and Fallopian 
tubes. 
(2) Menstruation and ovulation. 
(3) General condition of health. 
(4) Quantity and quality of food consumed. 
(5) Occupation. 
(6) Maternal age. 
(7) Climate and altitude, atmospheric conditions. 
(8) Individual peculiarities. 
(9) Circumstances of cohabitation. 
Paternal Secondary Laws.- 
(1) Physical condition of the testes and the seminal 
ducts, spermatic cord, vesiculae seminales, and the 
urethra. 
(2) Quantity and quality of food consumed by the 
individual. 
(3) Vitality of the husband. 
* (4) Age. 
(5) Occupation. 
(6) Clothing about the loins. 
200 SECONDARY LAWS. 
(7) Cohabitation. 
(8) Age at which puberty has been established. 
(9) Climate and altitude. 
201 
Maternal Secondary Laws. 
ist Maternal Secondary Law.-Physical condition of 
the ovary and Fallopian tubes.-Where we wish to 
control the production of sex it is most desirable to have 
the ovary in a perfectly normal condition in order that 
ovulation may take place at a fixed time after each 
menstruation, inasmuch as any pathological condition 
may hasten or retard ovulation. It is also necessary 
that the Fallopian tubes be in a normal condition to take 
up, transmit, and deliver to the uterus the ovum which 
has been matured and extruded from the Graafian 
follicle. The time consumed by the Fallopian tubes to 
deliver the ovum to the uterus from the Graafian follicle 
should not be longer than six hours; doubtless this is in 
many cases accomplished in a very few minutes, whereas 
in others it may be prolonged. Anything which may 
cause delay in the ovum reaching the Fallopian tube 
after its extrusion from the Graafian follicle will lessen 
the chance of sex control. The passage may be assisted 
and delay overcome by gravity, if the woman will lie on 
the side that produced the ovum, for from three to five 
hours just after insemination. This would cause the 
fluid and ovum from the Graafian follicle to gravitate to 
the fimbriated extremity of the tube, where it would be 
taken up and wafted toward the uterus. There is usually 
more or less pain or tenderness over the ovulating ovary 
just before, during, or after menstruation to indicate the THE CELLULAR DETERMINATION OF SEX. 
202 
side. In case the ovulating ovary is unknown, then the 
woman should lie on the side which is the more comfort- 
able, for from four to six hours-a period that will allow 
time for external migration of the ovum. 
2d Maternal Secondary Law.-Menstruation and 
ovulation.-Menstruation is commonly taken to consist 
in the periodical discharge of blood from the uterus. 
This, the most conspicuous objective phenomenon, is, 
however, only one act in a complicated process, of which 
the genital system is the focus, but upon which the entire 
organism is at work. The ovary in which resides the 
primum mobile of this process becomes greatly enlarged 
from an active hypersemia of the organ, which involves 
the entire vascular system of the pelvis. In a woman of 
the age of twenty-four, in her normal condition, when a 
Graafian follicle emerges from its dormant state to active 
development for the production of a mature ovum and 
its extrusion, the menstrual flow is usually its prodrome; 
if there are no abnormal conditions met with by the 
woman the follicle matures ready for rupture and extru- 
sion midway between the last day of one menstruation 
and the first day of a succeeding one. For variations 
from this rule the reader is referred to all of the secondary 
laws. Cessation of the menstrual flow is sometimes 
closely followed by its return without apparent cause. 
This is probably due to the maturity of a second Graafian 
follicle, in which event two ova are to be reckoned with 
when it is desirable to control the sex. In these cases 
the last day of the recurring flow is to be taken as the 
date to determine the time at which insemination should 
take place, instead of the last day of the normal menstrual 
flow. The loss of a double quantity of blood will retard SECONDARY LAWS. 
203 
the advancement to maturity of the second follicle, in 
most cases, as much as one day. 
3d Maternal Secondary Law.-Health.-The state of 
the general health will play a great part in the develop- 
ment of a Graafian follicle. The normal condition will 
tend to produce an ovule regularly and on the anticipated 
time; if from any reason this condition is lowered, a 
delay of the maturation of the Graafian follicle will 
follow the menstruation. I shall mention a few of the 
more common pathological conditions which will pro- 
duce a delay: the loss of an unusual quantity of blood 
during menstruation; the loss of blood from any cause; 
acute or chronic diarrhoea; hydragogue cathartics; 
continued overexertion; loss of sleep; profound shock 
produced from joy, sorrow, fear, fright, distress, or any- 
thing that will tend to lower the vitality or vigor of the 
individual. I think it best to wait for a normal con- 
dition, as children produced from an ovule matured 
under an abnormal condition are liable to deformity, 
birth-mark, and weakness of various parts of the body. 
The beginning of menstruation is the announcement of 
active development of the ovule, and it is from this 
time until the ovule has been extruded from the Graafian 
follicle that it is most receptive of impressions conveyed 
to it from the mother. A woman in good health has a 
full quantity of normal blood, which produces a smooth 
firm condition of the ovary; she is more susceptible to 
sexual passion; the sexual organs are readily filled and 
distended with blood; during the sexual union she is 
more active; her sexual organs become filled and en- 
gorged with blood, producing in them a hyper aesthetic 
condition which hastens orgasm; her ovaries are dis- 204 
THE CELLULAR DETERMINATION OF SEX. 
tended with blood to the point just short of rupture of 
the Graafian follicle, and when orgasm comes on, the 
follicle is instantly ruptured, the mucous membranes of 
the vagina, uterus, and Fallopian tubes are then flowing 
with a thin limpid mucous secretion, the ideal medium 
through which the spermatozoa readily pass to meet the 
ovum in the Fallopian tube. All of these conditions 
will lead to the production of a fine specimen of hu- 
manity, and the control of sex is at its maximum in 
such a case. 
4th Maternal Secondary Law.-Quantity and quality 
of food consumed by the individual.-Where a carbohy- 
drate or vegetable diet is used and not a great quantity 
consumed, a delay of the maturity and rupture of the 
Graafian follicle may be expected. Where a normal 
quantity of vegetables or carbohydrates and a moderate 
quantity of the proteids of meats and eggs are used, we 
may anticipate the maturity of the Graafian follicle in its 
normal period of time. Where there is a good quantity 
of both carbohydrates and proteids used we may antici- 
pate a still earlier maturity and rupture of the Graafian 
follicle. If a male child is desired, the chance may be aug- 
mented by the mother using as much meat and fats as 
possible, and only so much starchy foods as is absolutely 
necessary to prevent their want being felt, just a day or 
two before the anticipated sexual union. This is due 
to the rapid assimilation of proteids and fats, which are 
stored in the blood-vessels, from which they are assim- 
ilated. When the blood is loaded with proteids and fats, 
they are assimilated by the cells of the Graafian follicle 
very readily, and intrafollicular pressure is increased. 
This produces excitement in the female, and during sexual SECONDARY LAWS. 
205 
union she is more passionate and active and is more likely 
to reach orgasm, which ruptures the Graafian follicle 
and produces the best condition possible for male-produc- 
tion. " The bulk of the carbohydrate food reaches the 
liver as dextrose, or as dextrose and levulose, and these 
forms of sugar may be converted into glycogen in the 
liver cells by a simple process of dehydration " (Howell). 
A very small quantity of carbohydrates is stored in the 
muscular tissue which has a glycogenic function, as well 
as the liver, but this is consumed by the muscular tissue. 
It is the quantity stored up in the liver which is taken 
up by the blood and distributed to other tissues of 
the body slowly, uniformly, and just as it is needed. 
When starch is the principal food, it maintains a very 
regular and uniform blood-pressure; and the liver con- 
verts it into glycogen and stores it until needed by other 
tissues in the body. Such food creates a scarcity of 
protein in the blood, which retards to the minimum the 
production of fluid in the Graafian follicle. If the 
Graafian follicle reaches maturity very slowly, it fails to 
create the feminine passion, which it would do if devel- 
oped more rapidly. When the blood-vessels are not so 
full of blood, the sexual organs are not so sensitive, and, 
during sexual union, orgasm is not so liable to be reached. 
In the latter case the Graafian follicle is not so liable to 
be ruptured as it would be if it had been matured rapidly 
and well filled with fluid, and if the blood-vessels of the 
ovary were well filled and distended. 
5th Maternal Secondary Law.-Occupation.-Those 
who follow a regular occupation requiring active physical 
exercise, be it much or little, and maintaining their nor- 
mal physical vigor, will ovulate at the normal time in 206 
THE CELLULAR DETERMINATION OF SEX. 
relation to menstruation. If, however, there is a lowered 
physical condition we may anticipate a delay propor- 
tionate to the lowered vitality. In case the occupation 
is discontinued, an early extrusion of the ovule may be 
anticipated for the following two or three months. This 
is caused by an increased flow of blood to the ovaries. 
In persons devoted to ease and pleasure, we may find a 
condition just contrary to what we would ordinarily 
expect. Instead of an early maturity of the ovule, we 
find delays caused by occasional overexertion, such as 
dancing associated with loss of sleep, going on extended 
trips, assuming the duty of cook or servant in the home, 
all of which must be considered. In those of regular 
habits, who do not place a strain on their physical power, 
and who lead a sedentary life, we may anticipate the 
maturity of the Graafian follicle a little earlier than 
normal: a day or probably a day and a half. 
6th Maternal Secondary Law.-Age.-In the average 
nulliparous woman, of regular habits, vocation, and 
physical condition, at the age of twenty-four, ovulation 
will take place about midway between the cessation of 
one menstruation and the beginning of the following one. 
In those who menstruate every twenty-eight days, losing 
a normal quantity of blood for three days, the time for 
the maturation of the ovule and the ripened condition 
of the Graafian follicle would be at the end of twelve 
days and a half. Twelve hours may be deducted from 
this time for every year younger than the above-men- 
tioned age, and six hours added for each year older. In 
multiparae, where everything is equal to the conditions 
above described, we may anticipate the maturity of the 
Graafian follicle from two to three days sooner, for a SECONDARY LAWS. 
207 
period of two years, which is due to the increased flow' 
of blood to the parts. 
The following cases are of interest: " Early in March, 
1904, I attended Miss E. C., aged 50. She had passed 
' the change,' and had seen nothing for just two years, 
when, deeming herself safe from the possibility of preg- 
nancy, she ran the risk, and was duly delivered by me of 
a living male illegitimate child, nearly three years after 
having ceased to menstruate" (Dawson). Another some- 
what similar case is recorded by Hann in a woman of 49 
years, who gave birth to her thirteenth child-a boy- 
three years after the menopause; but in this case men- 
truation returned after the weaning of the child. 
The sexual organs of a young woman are more tender 
and sensitive than those in later life; and, during coition 
they, as a rule, are more passionate and reach orgasm 
from less activity on the part of the male. This, in turn, 
ruptures the Graafian follicle when near maturity, and 
produces the best condition possible for male-production. 
Many of the older women become indifferent and im- 
passionate, and remain in an apathetic condition during 
coition. When this is the case, the Graafian follicle is 
not ruptured during coition and the chance for male- 
production is at its lowest ebb. 
When the production of a male child is desired, it is 
the duty of the husband and wife to produce the best 
child possible, one that will be a pleasure to them, a help 
to the community in which he resides, a star to his nation, 
and a light to the world. This can be done only by 
bringing the best and freshest male and female seed 
together in their most active state; to accomplish which 
the indulgence of pure, loving passion on the part of the 208 
THE CELLULAR DETERMINATION OF SEX. 
female is absolutely necessary, in order that she may 
reach orgasm during the sexual union, and this union 
must take place at the proper time. 
To produce a female, the impassionate and apathetic 
condition on the part of the woman is as necessary as is 
the reverse condition for the production of a male, for 
the reason that the Graafian follicle must not be ruptured 
during the sexual union, but two or three days later when 
the spermatozoa have aged and become female-produc- 
ing; then the follicle should rupture of its own accord. 
This insures fertilization by the best spermatozoon for 
female-production. 
7th Maternal Secondary Law.-Climate in itself does 
not hasten or retard the maturity of the ovule in relation 
to menstruation, but a change of climate from a warm 
to a cold would hasten the maturation of the follicle 
possibly one or two days, and a change from a cold 
climate to a warmer one would retard the maturity about 
the same length of time. This change would not be 
effective for more than six months, after which the in- 
dividual would become acclimated. Rarefied air, or a 
high altitude, will retard the maturation of the follicle 
one or two days in those not acclimated; descending into 
a heavy atmosphere will hasten the maturity one or two 
days. Going from a normal atmosphere into an abnor- 
mally moist one will retard the maturity of the follicle 
one or two days; going from a moist to a dry and more 
normal climate will produce the reverse condition. 
8th Maternal Secondary Law.-Individual peculiari- 
ties.-In some of the best specimens of womanhood there 
is a production of female children all through life, and in 
others, on the other hand, there is an unbroken produc- SECONDARY LAWS. 
209 
tion of male children. This is due, in the former, to 
early insemination after the cessation of the menstrual 
flow, before it is possible to rupture the Graafian follicle 
during the sexual union, the spermatozoa ascending into 
the Fallopian tubes and, after a day or two, becoming 
female-producing before the extrusion of the ovum from 
the Graafian follicle. 
In the case of a chaste husband, the sex of the offspring 
is prone to be female, on account of the spermatozoa 
remaining in the vesiculae seminales until they are old 
and female-producing. When a woman has been pleth- 
oric during her younger days, and afterward becomes 
anemic from any cause, this change produces a shrinkage 
of the ovary, causing the peritoneal covering to be more 
susceptible of distention. When this condition is present 
the maturation of the Graafian follicle is very indefinite, 
as the peritoneal covering yields to the protruding 
Graafian follicle. This condition varies, however, in 
different women and in the same woman in proportion 
to the anemic condition present. When a male child is 
desired in these cases, the woman should go on a meat- 
and-fat diet, using a small quantity of starch and a large 
quantity of water for a day or two before insemination. 
This will increase the bulk of the blood and thus aid in 
distending the ovary, so that, during orgasm, the ovum 
is more liable to extrusion. Where the ovarian and the 
ovarian branch of the uterine arteries are abnormally 
small, the Graafian follicle is matured slowly and late; 
if these arteries are large, the Graafian follicle is matured 
rapidly and early. The sexual passion is more marked 
in some women than in others; those who are passionate 
and those whose sexual organs are sensitive and tender, 210 
THE CELLULAR DETERMINATION OF SEX. 
as the blonde, the plethoric, the young, the experienced, 
and those who have borne children, are more likely to 
reach orgasm during sexual union than the apathetic, 
brunette, lean, anemic, old, inexperienced, and nulli- 
parous. The mucous membrane of the blonde is very 
thin, tender, and sensitive. The sexual organs of the 
plethoric are more thoroughly filled and distended with 
blood, and the stretching of any mucous membrane 
renders it thinner, and more sensitive and tender to 
touch. The sexual organs of the young are more sensi- 
tive and tender than those of the older. The experienced 
woman understands how to bring herself to orgasm dur- 
ing the sexual union. Pregnancy produces an enlarge- 
ment of all the blood-vessels to and from the sexual 
organs, and after delivery there is a greater flow of blood 
to these parts during sexual union than in the nullipara; 
this congestion renders the Graafian follicle more liable 
to rupture during sexual union. Where a long time has 
elapsed between parturition and renewed sexual union, 
the blood-vessels will have returned to their former 
condition. The sexual organs of the apathetic are not 
so well filled and distended with blood as those of the 
passionate, and orgasm is a thing unknown to them. 
The mucous membrane of the brunette is thicker and far 
less tender and sensitive than that of the blonde. The 
sexual organs of the lean and anemic are very slow to fill 
with blood and never reach the distention observed in 
the full-blooded or plethoric individual. The sexual 
organs of older women become less tender and less sensi- 
tive to touch, and increasingly so with advancing age. 
The inexperienced do not, and could not be expected 
to, reach orgasm during the sexual union. The blood- SECONDARY LAWS. 
211 
vessels to and from the sexual organs of the nulliparous 
are smaller and are not so readily filled as those in women 
who have borne children. 
All those who reach orgasm during the sexual union 
have the power to produce male children when insemina- 
tion takes place at the proper time. It is a very diffi- 
cult problem to make an exact calculation when the 
rupture of a Graafian follicle will take place, and for that 
reason it will be hard to control the production of sex in 
those who do not reach orgasm during the sexual union. 
A Graafian follicle is not mature until it can be rup- 
tured at the moment of orgasm, during the sexual union. 
Its rupture may be produced by orgasm from three to 
five days sooner than it would if allowed to rupture of 
its own accord. In some cases it will not rupture at all 
without orgasm, as is beautifully illustrated in the case 
of Abraham and his wife Sarah. It seems that Abraham 
was unable to bring Sarah to orgasm and rupture a 
Graafian follicle, until three months after he had been 
circumcised, when he produced his son Isaac. 
9th Maternal Secondary Law. - Copulation. - Na- 
ture has designed that rupture of the Graafian follicle 
should take place at the moment of orgasm, during 
coition. During coition the female generative organs 
become filled and distended with blood. At the moment 
of orgasm there is a rigid contraction of all the plain 
muscular fibres which enter into the composition of the 
vagina and uterus, cutting off the arterial flow of blood 
to these parts and increasing the quantity of blood-flow 
to the ovarian branch of the uterine artery. At the same 
time this contraction causes a rush of venous blood 
from the vagina and uterus, filling and distending the 212 
THE CELLULAR DETERMINATION OF SEX. 
uterine venous plexus with blood, and it is more than 
probable that there is a rush of blood through the ovarian 
veins, causing a considerable, if not a total, obstruction, 
for a few moments, to the exit of venous blood from the 
ovaries. Furthermore, according to Schafer, there is a 
large number of plain muscular fibres in the stroma of 
the ovary near its attachment to the broad ligament. 
Contraction of these fibres prevents escape of blood from 
the ovary, while it would not materially retard the 
arterial flow to it. The control of these muscular fibres 
is most sure to be affected by sexual shock, orgasm pro- 
ducing their contraction. The above conditions, aug- 
mented by the contraction of the abdominal walls, would 
give considerable impetus to the rupture of the Graafian 
follicle. For this reason it is so essential that the woman 
should reach orgasm during the sexual union, when the 
production of a boy is desired. That rupture of the 
Graafian follicle is simultaneous with orgasm is conceded 
by Edgar, when he states that it " makes conception 
more probable." Therefore coition in the female is 
absolutely contra-indicated where we desire to control 
the production of sex, except at the time for insemination 
which should be carefully selected in advance. There 
should be no vaginal douche used during the day of 
insemination nor the day following, since it is liable to 
injure the spermatozoa and by so doing produce a weak- 
ened condition of any part or the entire body of the off- 
spring. Therefore it is unquestionably contra-indicated 
at this time. SECONDARY LAWS 
213 
Paternal Secondary Laws. 
ist Paternal Secondary Law.-Physical condition of 
the testicles, spermatic cords, vesiculae seminales, and the 
secretions of the glands which pour their contents into 
the convoluted seminiferous tubules, vasa recta, rete 
vasculosum, vasa efferentia, convoluted canal of the 
epididymis, vas deferens, and the urethra.-The produc- 
tion of male or female offspring depends very much 
upon the physical condition of the testicles and the tubes 
and the medium through which the spermatozoa pass to 
the vesiculae seminales, and of that part of the urethra 
through which the spermatozoa pass to the external os 
of the uterus, and of the secretions of the glands which 
pour their secretion into the passage-way of the sperma- 
tozoa. A normal condition of all the parts as enumerat- 
ed is conducive to male-production; on the other hand, 
where we find a lax, flabby, and yielding testicle and a 
dilated and enlarged epididymis and spermatic cord, or 
any obstruction internally or externally, acting as an 
impediment to the progress of the spermatozoa, there 
will be a tendency to sterility or female-production. 
2d Paternal Secondary Law.-Food, its quantity and 
quality.-A nitrogenous diet produces a rapid spermato- 
genesis, with consequent tenderness and small nucleus of 
the cells as explained on page 97. Where a carbohy- 
drate diet is used the spermatozoa are produced slowly 
and there is a tendency to the elaboration of the best 
specimens in both size and quality. The best sperma- 
tozoa are produced while the male is on a constant and 
well-regulated diet, with just enough of the carbohy- 
drates and a very small quantity of the proteids. Such 214 
THE CELLULAR DETERMINATION OF SEX. 
a diet produces large spermatozoa of great stamina. 
The consumption of a large quantity of the nitrogenous 
foods increases the bulk of blood, and the plethora 
renders the glans penis more sensitive to touch, so that 
less activity on the part of the male is necessary to 
eject the seminal fluid. 
3d Paternal Secondary Law.-An individual of great 
vitality may transmit that quality to his offspring; first, 
by the primordial-germ vitality; second, by a prolonged 
time afforded for maturation at the period when a pause 
in cell division intervenes between the spermatogonium 
and the spermatocyte, since a lengthened interval allows 
perfect development of all the structures appertaining 
to a spermatocyte; third, by the mother cell retaining 
the spermatozoa in contact until they have received a 
full supply of the chromatic and other elements necessary 
for the production of a similar individual. Or, in other 
words, where we desire to produce a fine specimen of 
humanity, it is absolutely necessary to build up the 
spermatozoa slowly from the primordial germ-cell to the 
spermatozoon, and this is done by slow spermatogenesis. 
This condition may be favored by hard physical labor, 
and a constant supply of carbohydrate food, with a very 
small quantity of proteids. Where there is a full supply 
of the protoplasm stored in the nucleus of the sperma- 
tozoa, the male-producing quality is increased propor- 
tionately. The sex-production of the spermatozoa from 
an individual of great vitality is controlled by the pri- 
mary law. 
4th Paternal Secondary Law-Age.-The age of the 
male plays a very important part in sex-production, and 
may be considered under the following heads: physical SECONDARY LAWS. 
215 
condition of the spermatozoa; size of the vesiculae semi- 
nales; the sensitiveness of the glans penis; and the 
power of the individual for sexual union. 
The spermatozoa of the young man are more tender 
and delicate, and the nucleus is not so large and well 
filled, owing to the rapid spermatogenesis; the nurse cell 
is forced to take care of its maximum number-from 
twelve to twenty. On the other hand, in the older in- 
dividual the spermatogenesis is not so rapid; the nurse 
cells accommodate the minimum number of spermatozoa 
-from four to eight. They thus obtain more food, 
more room, more time to mature in, and their vitality is 
greater, hence these spermatozoa retain the male-pro- 
ducing quality longer. 
The size and shape of the vesiculae seminales play a 
considerable role in sex control. In a male child at 
birth, the convoluted seminiferous tubules are represent- 
ed by a single row of cells, like a string of beads; their 
growth is very slow and they are ultimately developed 
into a solid tube which has no lumen until puberty 
approaches, when the lumen opens to transmit the 
spermatozoa and the secretions of the tubules. At about 
the time of puberty, when the lumen has opened and the 
seminal secretion begins to flow into the spermatic cord 
and the vesiculae seminales become filled, the sensitive 
nervous mechanism will not permit a great deal of dilata- 
tion at first. If the semen is not ejected voluntarily the 
sensitive nervous mechanism takes advantage of the 
individual while he is asleep and throws it off, and this 
condition continues for live or ten years and in some 
individuals longer, until the vesiculae seminales have 
been fully developed and dilated. At this time the 216 
THE CELLULAR DETERMINATION OF SEX. 
vesiculae seminales are in a mature condition, the nervous 
mechanism is not so sensitive, the tunics have been 
dilated and distended until they will hold a full normal 
quantity of the seminal fluid which is retained without 
discomfort. The individual can now go to sleep without 
fear of the nervous mechanism taking advantage of his 
slumber to eject the contents of the vesiculae seminales. 
Thus, we can easily understand why the spermatozoa 
will age readily in the older individual and become 
female-producing. Where it is desirable to produce a 
male child from an old individual, the contents of the 
vesiculae seminales should be ejected at least once a day 
for three or four days prior to insemination. This will 
make it certain that all the spermatozoa are young and 
male-producing. 
The sensitiveness of the glans penis varies in different 
individuals, and in the same individual at different times. 
The glans penis is more sensitive and tender in the blond 
than in the brunette; in the plethoric or full-blooded 
than in the anemic and lean; in the chaste than in the 
unchaste; in the young than in the old; in those with 
long prepuce than those with short prepuce; in the un- 
circumcised than in the circumcised. The blond, pleth- 
oric or full-blooded, chaste, young, those with long 
prepuce and the uncircumcised, all belong to the female- 
producing class. The brunette, lean, those who are un- 
chaste, old, those with short prepuce and the circumcised, 
all belong to the male-producing class. The glans penis 
of the blond is covered with a very thin, delicate mucous 
membrane. In the plethoric there is a greater distention 
of the glans penis during erection. Thevesiculae seminales 
of the chaste are usually filled with semen-a condition SECONDARY LAWS. 
217 
which produces a hyperaesthetic condition of the glans 
penis. The sexual organs of the young male are far more 
tender and sensitive than those of the older man. The 
uncircumcised and those with long prepuce have very 
tender and sensitive sexual organs. Very many of these 
classes of men eject the seminal fluid immediately after 
penetration, before the female has experienced any de- 
gree of shock from the sexual union. In such a case there 
is very little chance to control sex-production, unless a 
female child is desired, when these conditions are ideal. 
The glans penis of a brunette is covered with a thick 
mucous membrane which is less sensitive to touch than 
that of a blond. The glans penis of a lean man with little 
blood is not filled and distended as is that of the plethoric, 
and hence the organ is less sensitive. The vesiculae sem- 
inales are practically always empty in those who are 
unchaste, in which event the glans penis is far less sensi- 
tive to touch, and more activity on the part of the male 
is necessary to eject the semen. The glans penis of the 
older man is less sensitive to touch, and requires more 
activity on his part to eject the semen. When the prepuce 
is short and for any reason fails to cover the glans penis, 
it remains dry, is subject to thermal changes, and its 
rubbing against the rough clothing causes a growth of 
very thick mucous membrane which is far less sensitive 
to touch than when the glans is covered-a condition 
which is similar to that in the circumcised, as explained 
in the primary law (page 190). All such men are far 
more capable of bringing the female to orgasm than those 
above described, and it is these men who should be able 
to control the sex of their children. All of the male 
sexual organs-the testicles, the tubes through which 218 
THE CELLULAR DETERMINATION OF SEX. 
the spermatozoa pass, the spermatic cord, the vesiculae 
seminales, the penis, and all the accessory glands-must 
be in a normal condition before one can hope for the 
control of the sex of the children. 
5th Paternal Secondary Law.-Occupation.-All those 
who constantly and continually exercise all the muscles 
in their body, who work hard and labor long, who do a 
reasonable amount of brain work and take just enough 
food to prevent any accumulation of fat, will augment 
the production of highly vital and large spermatozoa. 
Men who live an inactive life are prone to rapid sperma- 
togenesis, which produces a delicate spermatozoon with 
small nucleus. Those who follow an occupation which 
causes compression of the testicles, such as horseback 
riding, shoeing horses, and wearing very tight clothing 
about the loins, are liable to produce weak, delicate male 
children. Compression of the testicles causes the separa- 
tion of the spermatozoa from their mother cells before 
they are fully matured. This renders them male-produc- 
ing owing to their very rapid movements. The sperma- 
tozoon, when prematurely detached from its mother cell, 
is very rapid in its movements, and is thus enabled to 
lacerate the vitelline membrane of the ovum and pass 
through into the cytoplasm, carrying with it the sex- 
membrane, body, and tail, producing a male. In such 
a case a male is produced by the rapidity of the move- 
ment of the spermatozoon and not by the large size of its 
nucleus, though as a rule it is necessary in male-pro- 
duction that the nucleus be large or that great activity 
be displayed on the part of the spermatozoon. It is im- 
possible to produce a female unless the nucleus is more 
than half covered by the sex-membrane and the move- SECONDARY LAWS. 
219 
ment of the spermatozoon is rather slow, and this is the 
reason why the female is uniformly smaller than the male. 
6th Paternal Secondary Law.-Clothing about the 
loins.-The protection of the testicle by clothing is one of 
the evils of our civilization, for just in proportion as these 
organs are protected, will tenderness and delicacy be 
transmitted to our offspring. The explanation is found 
in the warmth which increases the blood-flow to the 
parts by dilatation of the blood-vessels and more or less 
relaxation of all the tissues which enter into the composi- 
tion of the testicles and their tunics. Relaxation and 
dilatation of the blood-vessels hasten puberty and bring 
on a rapid production of spermatozoa, both of which con- 
ditions are conducive to delicacy in the offspring. The 
clothing about the testicles should be both thin and 
loose. Keeping the testicles cool quickens the circulation 
and brings about a healthy state of these organs and the 
tunics. Tight clothing exerts pressure upon the testicles 
and causes detachment of the spermatozoa from their 
mother cells prior to their full development. When 
spermatozoa are prematurely detached they are for a 
short time more active than those more fully developed 
and it is to the prematurely detached cells that the 
greater mortality of male children is due. 
7th Paternal Secondary Law.-Copulation.-A mod- 
erate indulgence in coition during early manhood will 
serve to prevent an overdistention and a permanent 
enlargement of the vesiculae seminales. Indulgence in 
excess produces rapid spermatogenesis which renders the 
nuclei of the spermatozoa snjall, and they soon become 
female-producing. Where the production of a male 
child is desired the vesiculae seminales should be emptied 220 
THE CELLULAR DETERMINATION OF SEX. 
at least twice a week for two or three weeks, and once a 
day for three days prior to insemination. The last 
emission should take place one day before the insemina- 
tion. Where it is desired to produce a female the sper- 
matozoa should be retained in the vesiculae seminales 
at least five days before insemination. 
8th Paternal Secondary Law.-Puberty.-When pu- 
berty is established early in life a hastened development 
and dilatation of the vesiculae seminales will result. 
Early advancement to puberty produces rapid spermato- 
genesis. 
gth Paternal Secondary Law.-Climate and altitude. 
-The change from a warm to a cold climate or from a 
dense atmosphere to a lighter one will cause very little 
difference in the size and quality of the spermatozoa 
produced. Those who live in a warm or tropical climate 
will advance to manhood sooner than those who live in a 
temperate climate and their lives will be shorter. CHAPTER X. 
FINAL INSTRUCTIONS. 
Male-Production.-The spermatozoon must reach the 
ovum before it becomes old and female-producing. To 
do this it is necessary to inseminate at a time when 
orgasm of the female will rupture the Graafian follicle. 
Orgasm in the female will probably rupture a follicle 
from three to five days sooner than it would if allowed 
to burst of its own accord. To produce a male in a 
normal woman, fourteen days from the last day of 
menstruation should be elected for the date of insemina- 
tion. It is better not to cohabit after the election date 
of insemination, inasmuch as orgasm of the female is 
liable to expel the fertilized ovum before it has become 
attached to the wall of the uterus. If cohabitation is 
to follow, it should not begin sooner than three or four 
days and not continued longer than to within three days 
of the anticipated menstruation. It is not known how 
long after insemination a spermatozoon is capable of 
fertilizing an ovum. It depends on how well developed 
it is when it leaves the mother cell (cell of Sertoli), how 
long it is in reaching the vagina, and the medium to 
which it has been subjected. It is probable that the best 
of the spermatozoa are capable of fertilizing an ovum 
from two to five days after insemination. If a woman 
fails to become pregnant for six months after observing 
the instructions as above given, then elect a date twelve 
days after the menstrual flow and continue that for eight 
221 222 
THE CELLULAR DETERMINATION OF SEX. 
months. Then if conception has not taken place, a still 
shorter period of ten days after menstruation should be 
elected, and this be repeated for twelve months. If the 
woman still fails to conceive, a shorter period of eight 
days after the flow should be elected for insemination, 
and repeated four months; then, if conception has not 
taken place, a shorter period of six days after the flow 
should be elected for insemination. This will undoubted- 
ly include all those who mature the Graafian foolicle very 
early after menstruation. For male-production rupture 
of the Graafian follicle during insemination is imperative 
and the greatest stimulus to its rupture is orgasm during 
the sexual union, which may be augmented by the woman 
going on a proteid diet and drinking an abundance of 
milk and water or any fluid except those containing 
alcoholic stimulants, such as wine, champagne, beer, ale, 
or whisky. These must not be used in any quantity by 
the female. After insemination she should lie for three 
or four hours on the side of the ovary which matured 
the ovum; if it is not known which ovary matured the 
ovum, she should choose the most comfortable side to lie 
on and remain on that side for five or six hours to assist 
by gravity the ovum to the fimbriated extremity of the 
Fallopian tube, where it can be taken in by the ciliated 
epithelium and delivered to the spermatozoa in the 
Fallopian tube. The above instructions are for those 
women who are in a normal condition. If anything un- 
usual presents itself which would delay maturity of the 
follicle, due allowance must be made for it as indicated 
in the secondary laws. I furthermore state that the loss 
of blood from any cause-diarrhoea, hydragogue cathar- 
tics, scarcity of proteids in the diet, illness of any kind, FINAL INSTRUCTIONS. 
223 
overwork, great grief or joy-will delay the maturity of 
the Graafian follicle. To prepare the male for the pro- 
duction of a fine male child, he should go on a starch 
diet for two or three months prior to the anticipated in- 
semination, work hard and constantly, remain secluded 
from the female, see that the clothing is loose about the 
testicles and that they are not subjected to any pressure 
just five or six days before the anticipated date of 
insemination. The semen should be ejected once each 
day for four or five days before insemination. This will 
insure the presence of the very best specimens of sperma- 
tozoa and at the same time require more activity on the 
part of the male to reach orgasm and will assist the 
female to orgasm. If the male has a hypersesthetic glans 
penis, this may be counteracted by circumcision or by 
the use of an alcoholic stimulant just before insemination. 
The male should abstain from the use of an excessive 
quantity of fluid or drink just prior to insemination. 
The female must not allow sexual union from the last 
day of the menstrual flow until the date elected for in- 
semination, as it would be liable to rupture the Graafian 
follicle, and propulsion of the ovum to the vagina would 
follow. Pregnancy always increases the size of the 
blood-vessels to the generative organs-to the ovaries- 
and they will mature the Graafian follicles sooner after 
the menstrual flow for a period of two or three years. 
Female-Production.-Insemination may follow the 
cessation of the menstrual flow until five days after it, 
when it must cease until sixteen days after the last day 
of the menstrual flow. Orgasm of the female must 
not take place in any sexual union from the last day of 
the menstrual flow to the fifth day following. An alco- 224 
THE CELLULAR DETERMINATION OF SEX. 
holic stimulant, such as wine, whisky, champagne, beer, 
or ale, taken just before insemination will prevent orgasm 
on her part. The male, in this case, must abstain from 
any alcoholic beverage and the use of a good quantity 
of proteids may be advised for a day or two before in- 
semination as this will hasten orgasm. A starch diet 
should be used for two months or at least six weeks 
before insemination, when a fine, healthy, stout child is 
desired, and it is the duty of a father to devote as much 
attention to the production of a daughter as to that of 
a son. 
The sex of any one animal belonging to the mam- 
malian group may be controlled by bringing fresh 
spermatozoa (from Sertoli cell) to the ovum, at a time 
when the Graafian follicle is ruptured. This is almost 
without exception several days after oestrum has been 
inaugurated. 
Control of Sex in the Class Aves or Bird Family.- 
When the production of males is desired, the female 
should have begun laying before mating. Mating must 
not be allowed for thirty days prior to the selected 
date. This eliminates all chances of a previous fertil- 
ization of the eggs. Mate with an active cock in the 
prime of life, one which has had access to females for 
several days previous to mating; this insures the presence 
of active male-producing spermatozoa in the vesiculse 
seminales. The first eggs laid after such mating are 
very valuable, inasmuch as the birds produced from 
them are far superior to those from eggs laid later. The 
eggs laid the second day after mating are fertilized. 
It may be desirable to control the sex in birds which 
lay two or three eggs for a setting. This can be done by FINAL INSTRUCTIONS. 
225 
removing the eggs from the nest each day, allowing only 
one to remain in the nest; by so doing the bird will lay 
for an indefinite time. The production of eggs is con- 
trolled by the bird's diet; when she sets she refuses food 
and drink to the extent that the production of eggs 
ceases. This condition renders it possible to control the 
sex in the bird family. 
A bird seldom begins to set before she has her appro- 
priate number of eggs, which is the number of young she 
is capable of taking care of. 
The production of female birds is more difficult. In 
this case the male must not be allowed to mate other 
females for three weeks prior to mating the female in 
question. The female should not be mated until she is 
ready to lay, and then be permitted only three or four 
matings in one day, with a male which has not mated 
for three weeks. This insures the presence of female- 
producing spermatozoa in the vesiculae seminales and 
spermatic cord. The cock should be past the prime of 
life, and rather inactive. A cock in this condition will 
produce at least eighty per cent of female offspring from 
the first four females mated. The first three or four eggs 
from each female bird so fertilized will produce birds far 
superior to those from eggs laid later. To improve the 
stock of birds, this method of selection will be found 
superior to any advanced heretofore. 
Control of Sex in the Reptile Family.-The general 
anatomy and physical condition of reptiles are so closely 
related to those of birds that we may use the same 
methods to control sex in them, as above given for birds. 
Control of Sex in the Fish Family.-In the case of 
fish that are produced from the ova and spermatozoa 226 
THE CELLULAR DETERMINATION OF SEX. 
which are brought together by the intervention of man, 
the sex may be controlled very readily. 
Males can be produced by placing both ova and 
spermatozoa in water at such a temperature that fertil- 
ization may be hastened. This will insure the prepon- 
derance of males. 
Females can be produced by subjecting the spermato- 
zoa to water at a temperature in which fertilization 
would take place and allowing them to remain until the 
nucleus is smaller in diameter than that of the sex- 
membrane; then introduce the ova into the water, and 
all eggs will produce females. To determine the time 
required, it will be necessary to examine the spermatozoa 
with a microscope. Some spermatozoa become female- 
producing much sooner than others, and the temperature 
of the water in which the spermatozoa are kept will play 
its role in female-production. BIBLIOGRAPHY. 
The titles included here are arranged in alphabetical 
order according to the system adopted in other recent 
works. Each author's name is followed by the number 
of the edition or the year of publication (abbreviated to 
the last two digits in all years between 1869 and 1911, 
inclusive): 
W. Morrant Baker, F.R.C.S., Hand-book of Physiology, '96. 
Fancort Barnes, M.D., Obstetrics, '85. 
Robert Barnes, M.D., Obstetrics, '85. 
Edson S. Bastin, A.M., Botany, '95. 
Books of the Old Testament. 
Brewster, in his note on Determination of Sex in Man. American 
Anthropologist, vol. 8, '06. 
Gary N. Calkins, Ph.D., Protozoology, '09. 
Laura A. Calhoun, Sex Determination and Its Practical Applica- 
tion, To. 
William Francis Campbell, M.D., Surgical Anatomy, '08. 
W. E. Castle's No. 4 Contribution from the Zoological Labora- 
tory of the Museum of Comparative Zoology at Harvard College. 
A. J. Cook, Manual of the Apiary, eighteenth edition. 
John Cowan, M.D., The Science of a New Life, '69. 
B. Farquhar Curtis, M.D., Practice of Surgery, third edition. 
John C. Dalton, M.D., Physiology, '82. 
Charles Darwin, M.A., F.R.S., The Descent of Man. 
E. Rumley Dawson, L.L.C.P., London; M.R.C.S., England, 
Control of Sex. 
J. Clifton Edgar, Obstetrics, '03. 
Encyclopaedia Britannica, ninth edition, and eleventh edition. 
Rt. Rev. Samuel Fallows, A.M., D.D., LL.D., Encyclopaedia of 
the Bible. 
Julius Freidenwald, M.D., Diet in Health and Disease, To. 
Austin Flint, M.D., LL.D., Human Physiology. 
Henry Gray, F.R.S., Anatomy, 'Sy-'oj. 
Charles Wilson Greene, A.M., Ph.D., Physiology, sixth American 
revision. 
227 228 
BIBLIOGRAPHY. 
Henry N. Guernsey, M.D., Plain Talk on Avoided Subjects, '07. 
Richard Hertwig, General Principles of Zoology, '97. 
William H. Howell, Ph.D., M.D., LL.D., Physiology, third 
edition. 
Thomas H. Huxley, Man's Place in Nature. 
Thomas H. Huxley, F.R.S., Study of Zoology, '06. 
Thomas H. Huxley, LL.D., F.R.S., Anatomy of the Vertebrated 
Animals, '02. 
Flavius Josephus, History of the Jews. 
John Henry Kurtz, D.D., Manual of Sacred History. 
J. Playfair McMurrich, A.M., Ph.D., Manual of Human Embry- 
ology, third edition. 
Charles Sedgwick Minot, Human Embryology, '92. 
H. H. Milman, D.D., History of the Jews. 
Thomas H. Montgomery, Jr., The Cellular Basis of the Determina- 
tion of Sex, vol. 1. International Clinics, 'll. 
Hugh Northcote, M.A., Christianity and Sex Problems, '07. 
T. Jeffrey Parker, B.Sc., London, Zootomy, '95. 
Theophilus Parvin, M.D., LL.D., Obstetrics, '90. 
Thomas Pickering Pick, Surgery, '99. 
George A. Piersol, M.D., Sc.D., Histology, eighth edition. 
George A. Piersol, M.D., Sc.D., Anatomy, '07. 
R. C. Punnett, M.A., On Nutrition and Sex Determination in 
Man. Cambridge Philosophical Society Proceedings, vol. xi. 
E. A. Schafer, LL.D., Sc.D., F.R.S., Essentials of Histology, 
seventh edition. 
Septimus Sisson, S.B., V.S., Veterinary Anatomy, To. 
T. Gaillard Thomas, M.D., LL.D., Diseases of Women, sixth 
edition. 
W. J. Truitt, M.D., Know Thyself, '07. 
James Tyson, M.D., Practice of Medicine, second edition. 
Prof. Wm. H. Walling, A.M., M.D., Sexology, '09. 
Henry R. Wharton, M.D., Practice of Surgery, third edition. 
Edmund B. Wilson, Ph.D., The Cell in Development and Inherit- 
ance, '06. 
Gerald F. Yeo, M.D., Dubl.; F.R.C.S., Manual of Physiology, '90. INDEX. 
Age, maternal, 206. 
paternal, 214. 
spermatozoon, 82, 83. 
Amenorrhoea, 126, 127. 
Aphides (plant-lice), 158. 
Axial filaments, .93, 95. 
penetrating the nucleus, 83. 
Bartholin, glands of, 76. 
Bibliography, 229. 
Birds, determination of sex, 169, 
171, 174, 224, 225. 
spermatozoa, 101, 103, 104, 
156. 
vitality of spermatozoon, 
168. 
Body of spermatozoon, 89, 90. 
male-producing qualifica- 
tion, 87, 88, 149, 150. 
effect of, 163, 164. 
Bursa, ovarian, 44, 45. 
Calendar of menstruation and 
marriage, 180, 183. 
Cell, size of, 164. 
Cellular determination of sex, 
149. 
Centrosome, 118, 121. 
Clitoris, 76, 77, 78. 
Corpus luteum, 49. 
Cowper, glands of, 41. 
Cremasteric fascia, 27. 
Cytoplasm, 116. 
Dartos, 26. 
Delayed pregnancy, 189. 
Descent of the testes, 22. 
Determination of sex, 80, 81, 
149, 150, 152. 
Development, generative organs, 
19. 
female, 42. 
male, 20. 
Graafian follicle, 49, 109. 
ovum, 106. 
seminiferous tubules, 20. 
Distinction of sex, 19. 
Dog, control of sex in, 174, 178. 
Egg, formation of, 63. 
Ejaculatory ducts, 38. 
Epididymis, 24, 25, 
Fallopian tubes, 57. 
course pursued, 59. 
development, 57. 
diseases of, 72. 
function, 61. 
structure, 60. 
Fascia propria, 27. 
Female generative organs, 42. 
external, 74. 
Fertilization of ovum, 150, 151. 
birds, 62. 
fish, 167. 
human, 60. 
reptiles, 62. 
Female-production, 98, 149, 151, 
160, 171, 176, 183, 184, 223, 
225, 226. 
Filaments, axial, 83, 89, 93. 
broken, 85, 86. 
229 230 
INDEX. 
Filaments, extracted, 83, 89. 
Final instructions, control of 
sex, 221. 
Fixation of the ovum, 70. 
Genital ridge, 19. 
Germ-epithelium, 20. 
Giant spermatozoa, 102. 
Giraldes, organ of, 21. 
Glands of Bartholin, 76. 
of Cowper, 41. 
prostate, 40. 
Gonorrhoea, in the female, 72. 
Graafian follicle, 48. 
analogue, 143. 
development, 49, 109. 
rupture, 48. 
analogue to, 48. 
Gravitation, 45. 
Gubernaculum testis, 22. 
Guide to sex control. See Sex. 
Heteroparthenogenesis, 158. 
History of sex determination, 13. 
Hydatid of Morgagni, 20. 
Hymen, 76. 
Inheritance limited by sex, 
165. 
Insemination, 145. 
Intercolumnar fascia, 27. 
Labia majora, 74. 
minora, 75. 
Male organs of generation, 19. 
Male-production, 80, 98, 149, 
150, 154, 160, 162, 170, 176, 
177, 221, 225, 227. 
Maternal secondary laws, 200. 
age, 206. 
Maternal climate, 208. 
copulation, 211. 
food, 204. 
health, 203. 
individual peculiarities, 208. 
menstruation and ovulation, 
202. 
occupation, 205. 
ovaries and Fallopian tubes, 
201. 
Maturation of ovum, 121. 
Menstruation, 123. 
cause of, 136. 
constitutional phenomena, 
I3I- 
cycle, division of, 134. 
delayed, 128. 
diet, 130. 
habitation, 128. 
latitude, 128. 
local phenomena, 131. 
occupation, 130. 
race, 130. 
relation to ovulation, 135. 
second blood-flow, 143. 
sexual energy, 125. 
synonyms, 123. 
temperature, 128. 
universal law, 130. 
Micropile, 112. 
Mons veneris, 74. 
Mullerian ducts, 20. 
Nucleus of ovum, 116. 
of spermatozoon, 79. 
laceration of, Fig. 18. 
separated from the sex- 
membrane, 83, 84, 
89, 103. 
staining, 86. 
structure, 79. INDEX. 
231 
Nucleoli, 118. 
Nurse cell (or cell of Sertoli), 32> 
33> 97- 
Occupations of men in my 
statistics, 185. 
CEstrum, 175. 
Os uteri, 52. 
Ovarian bursa, 44. 
Ovaries, 42. 
hilum, 45. 
serous covering, 47. 
size, 44. 
structure, 47. 
weight, 44. 
Parthenogenetic reproduc- 
tion, 159. 
Paternal secondary laws, 213. 
age, 214. 
altitude and climate, 220. 
clothing about loins, 219. 
copulation, 219. 
food, 213. 
generative organs, physical 
condition of, 213. 
occupation, 218. 
puberty, 220. 
vitality, 214. 
Penis, 41. 
Precocity in the female, 125. 
Pregnancy delayed, 189. 
after menopause, 207. 
Prevention of sterility, 189. 
Primordial ovum, 108. 
Primary Graafian follicle, 109. 
Processus vaginalis, 24. 
Prostate gland, 40. 
size, 40. 
structure, 40. 
Rupture of the Graafian folli- 
cle, 136. 
its cause, 137. 
relation to menstruation, 
141. 
Scrotum, 26. 
Secondary laws, maternal and 
paternal, 200. 
Select fertilization, 69, 224. 
Seminal fluid, 102. 
Seminiferous tubules, 29. 
length of, 30. 
structure, 31. 
Sertoli cell, 31, 97, 98. 
Sex, control of in the bird, 172, 
224. 
human, 178, 221. 
reptile, 225. 
fish, 225. 
Sex determination, 165. 
Sex-membrane, 82. 
removed from nucleus, 84, 
89, 103. 
in fertilization, 86, 87, 
88. 
Sexual energy, 125. 
Size of male and female com- 
pared, 163. 
Statistics of 1,000 families: 
births, 184. 
occupation of men, 185. 
pregnancies, first, 164. 
the age, weight, and height 
of men and women 
who produced male 
children ten months 
after marriage, 185. 
those who produced 
girls nine months 
after marriage, 187. 232 
INDEX. 
Statistics of twins, 185. 
Sterility, prevention of, 189. 
Structure of the testis, 28. 
Spermatids, 34. 
Spermatocyte, 34. 
daughter, 34. 
Spermatogenesis, 32, 35, 97, 98. 
Spermatogonia, 31. 
Spermatozoon, 79. 
bat, 153. 
bullfinch, 156. 
cock, 101, 103, 104. 
human, 80, 81, 91. 
insect (calathus), 157. 
pike, 155. 
raja, 153. 
sturgeon, 155. 
ultra-active, 69, 70. 
under the cover glass, 100, 
101, 102. 
coiled, 102. 
Tables. See Statistics. 
Testis, coverings, 26. 
dimensions and weight, 25. 
Tubuli recti, 34. 
Tunica albuginea, 28. 
vaginalis, 28. 
Twins, identical, 102. 
Uterus, 51. 
appendages, 57. 
capacity, 146. 
ligaments of, 52. 
mucous membrane, 56, 
structure, 54. 
vessels and nerves, 57. 
Vagina, 73. 
Vasa efferentia, 36. 
Vasa recta, 36. 
Vas deferens, 36. 
structure, 37. 
Vesiculae seminales, 37. 
milking, 40. 
rectal touch, 40. 
relations, 38. 
structure, 39. 
Vitality of spermatozoa: 
bird, 168. 
human, 100. 
Vitelline membrane, 112. 
Wilson's X element, 162. 
Wolffian body, 19. 
Zona radiata, 114.