Repi'in ted from 
TIIE JOURNAL 
OF 
Comparative Medicine and Surgery, 
July, 1887. 
Art. XX. A CRITICAL COMPARISON OF A 
SERIES OF SKULLS OF THE WILD AND 
DOMESTICATED TURKEYS. 
(Melegris gallopavo mexicana and M. domestica.) 
BY K. W. SHUFELDT, C. M. Z. S 
Captain, Medical Corps, U. S. Army. 
As one would surely have predicted beforehand, Mr. 
Darwin, when he came to compare series of skulls of the 
numerous varieties of the domesticated fowls, with the 
skull of G. bankiva, and similarly, skulls of a number of spe- 
cies of tame ducks with the wild duck, found some very 
striking differences among them. So far as I have been 
able to ascertain, however, he never compared the skulls 
of the tame and wild turkeys; and so far as his compari- 
sons of fowls and ducks are concerned, I believe they are 
principally intended to show the great variation that has 
taken' place in these parts, and the marked departures 
from the wild type in the case of the fowl and duck, re- 
spectively. 2 
Skulls of Wild and Domesticated Turkeys. 
Indeed, it would be difficult I imagine, unless one could 
secure skulls from an entire line of fowls showing the 
gradual changes in them as they descended from the parent 
wild stock, to demonstrate anything else. The same remark 
applies, of course, to the ducks. I am not aware that any 
such a series has ever been made, with the view of pointing 
out these interminate variations, as they must have 
occurred in some of the breeds. It would not be difficult, 
however, to picture to our minds the shading differences 
that would take place in the skulls in a line of fowls ex- 
tending between G. bankiva, and, for instance, a white- 
crested Polish Cock. 
With respect to the turkeys we have some very interest- 
ing data to start from, and of such a character, I think, 
that when taken in connection with the facts that I intend 
to present in this paper, it will lend some additional light 
to certain phases of this question. 
In the first place, our ornithologists now recognize two 
well-defined species of wild turkeys in the avifauna of the 
United States, viz : M. gallopavo, and M. g. mexicana: then 
there are in this country alone, several very well-marked 
varieties of the domesticated turkey. So there seems to be 
no reason but that by careful selection and breeding we 
might not in time have quite as many varieties of turkeys 
as we now have of chickens, and presenting the same extra- 
ordinary differences in form and plumage. 
Further, to quote quite extensively from Mr. Darwin’s 
“ Animals and Plants under Domestication,” (Yol I, pp. 
352-355), and omitting the authorities from whom lie de- 
rived some of his information, we find that: “ It seems 
fairly well established by Mr. Gould, that the turkey, in 
accordance with the history of its first introduction, is 
descended from a wild Mexican species (.Meleagris mexicana) 
which had been already domesticated by the natives before 
the discovery of America, and which differs specifically, as 
it is generally thought, from the common wild species of 
the United States.” 
“ Some naturalists, however, think that these two forms 
should be ranked only as well-marked geographical races. Skulls of Wild and Domesticated Turkeys. 
3 
However this may be, the case deserves notice because in 
the United States wild male turkeys sometimes court the 
domestic hens, which are descended from the Mexican 
A'ig.A. 
Fif.n 
Fig. A. Superior aspect, life size, of a skull of a wild turkey, M. g. mex 
icana. 
Fig. B. The same view of a skull of the domesticated turkey, also life size. 
Drawn from adult specimens by the adthor, and mandibles removed in each 
case, pmx, premaxillary ; pi, palatine ; mx, maxillary ; l, lacrymal ; f, fron- 
tal ; mx. p., maxillo-palatine ; n., nasal; elh., ethmoid ; ju., jugal ; qj., quad- 
rato-jugal; q., quadrate; so., supraoccipital ; sq., squajnosal ; pf., postfron- 
tal process. 
form, and are generally received by them with great 
pleasure. Several accounts have likewise been published 4 
Skulls of Wild and Domesticated Turkeys. 
of young, reared in the United States from the eggs of the 
wild species, crossing and commingling with the common 
breed. In England, also, this same species has been kept 
in several parks; from two of which the Rev. W. D. Fox 
procured birds, and they crossed freely with the common 
domestic kind, and during many years afterwards, as he 
informs me, the turkeys in his neighborhood clearly showed 
traces of their crossed parentage * * * English turkeys are 
smaller than either wild form. They have not varied in any 
great degree ; but there are some breeds which can be distin- 
guished, as Norfolks, Buff oiks, Whites, and copper-colored 
(or Cambridge), all of which, if precluded from crossing 
with other breeds, propagate their kind only.” Darwin 
then goes on in the same place to point out some of the 
marked characteristics of the other varieties, one or two of 
which were conspicuously crested. He concludes by say- 
ing that “In India the climate has apparently wrought a 
still greater change in the turkey, for it is described by Mr. 
Blyth as being much degenerated in size, ‘ utterly incapa- 
ble of rising on the wing,’ of a black color, and with 
the long pendulous appendages over the beak enormously 
developed.” 
With these facts before us, I conceived it would be of in- 
terest, if not of actual importance to compare a good se- 
ries of selected skulls of M. g. mexicana, with a series of 
skulls of that domesticated form of the turkey which 
shows in 'its external characters evidences of being still 
closely affined to the wild stock. Then taking into con- 
sideration the number of years since this bird has been do- 
mesticated, I thought it might be possible to discover those 
definite characters in the skull that already showed a de- 
parture from the corresponding features in the skull of the 
wild turkeys. The latter are to be found in the forests 
within a mile of my. present residence, and this gave me 
the opportunity, which I have availed myself of, of secur- 
ing a fine series of the skulls of this form. Another series 
representing the variety of the tame turkey alluded to in 
the last paragraph, were collected for me in Chicago, by 
Mr. H. K. Coale, the president of the Ridgway Ornitholog- Skulls of Wild and Domesticated Turkeys. 
5 
ical Club of that city ; and I am under great obligations to 
him for the evident care he took to select the proper kind 
Fij.C. 
Fig. C.—Under view of the skull of Meleagris gallopavo mexicana; with 
inaudible removed, Life size adult; from the same specimen shown in figure 
A. Drawn by the author, pmx, premaxillary; mxp., maxillo-palatine ; mt, 
maxillary ; pi, palatine ; j, jugal; f, frontal ; qj, quadrato-jugal ; eu, Eusta- 
chian tube, anterior aperture; bt, basi-temporal; oc, occipital condyle; so., 
supraoccipital; q, quadrate; pf, postfrontal; pg, pterygoid; rbs., basi- 
sphenoidal rostrum; l, lacrymal ; vx. vomerine ossifications ; n, nasal. 
of material. I prepared the skulls of both of these series 
myself, as the heads came to me in the flesh. Not being 6 
Skulls of Wild and Domesticated Turkeys. 
familiar with any name, as having previously been be- 
stowed upon it by former authors, for this variety of the 
tame turkey, I have designated it for convenience sake, 
the M. g. domestica. 
When we come to simply superficially compare the skull of 
one of these wild turkeys with the skull of one of the domes- 
ticated ones, we appreciate that same difference which we 
find upon a similar comparison to distinguish the skull of 
a cock G. bankiva, and any of the typically domesticated 
fowls. It seems to consist in a lightness, a pneumaticity, 
accompanied by a certain sharpness of the details of the 
skull, an angularity, if we may so express it, in the case 
of the wild bird, as contrasted with an evident thickness 
and density of the hone, together with a general mellow- 
ing down of its principal free edges, producing a certain 
lack of sharpness, in the case of the domesticated one. 
Now to compare the details, I have chosen the skull, one 
from my series, of a fine adult male specimen of M.g. mexi- 
canct, it having all the features of a skull of a wild turkey 
well exemplified. This skull I have drawn life size in the 
figures illustrating this paper (Figs. A, C, D and F). With 
the same care I have selected for illustration oiTe of the 
skulls of the series representing my tame turkeys, which 
seems to present all the salient characters seen in the skull 
of M. g. domestica (Figs. B, E and G). It was also an adult 
male specimen. 
Viewing these two skulls upon their superior aspects, as 
shown in figures A and B, we find the form of the pre- 
maxillary hone essentially very much the same in both 
birds ; and, I fail to find any distinctive differences among 
them that have any claim to constancy. It will be noticed 
that the backward-extending supero-median nasal process 
of this hone retains throughout life its longitudinal divi- 
sion into two slips. Between the posterior extremities 
of these, in all specimens that I have examined, both wild 
and tame, it is possible to discern the unlying ethmoid (eth). 
Coming next to the nasal hones (n), we find that they also 
have pretty much the same shape and relation in the two 
skulls under consideration. I have always noticed, however, Skulls of Wild and Domesticated Turkeys. 
7 
that in the skulls of wild turkeys, the posterior borders of the 
nasals indistinguishably fuse with the adjacent frontals, 
and in them this fronto-nasal region is more concaved than 
it is in the skulls of the domestic turkeys. There is one 
skull of a tame turkey in my series, and hut one, that shows 
this absorption of the fronto-nasal suture. But this skull 
also exhibits other features that partake more or less of the 
characteristics of the skull of a wild turkey. 
I am inclined to think that it will be found though, that 
the persistency of this suture in the skull of adult tame 
turkeys, marks one of those differences that will eventually 
become one of its established distinctive characters. And 
here it will he as well to remark that the fusing of- those 
hones of the skidl that commonly have the sutures among 
them obliterated in adult life, takes place, as a rule, at a 
much later date in domesticated turkeys, than it does in 
the wild birds. It is not an uncommon thing to find the 
bifrontal suture present in old barn-yard gobblers. What 
I have said in regard to the premaxillary and nasal bones, 
is well shown in figures A and B ; we may also see there 
the usual form assumed by the lacrymal (/), which latter 
is a largely developed element of the skull in all turkeys. 
In the vast majority of skulls of both species this bone 
articulates with the external free edge of the posterior 
moiety of the corresponding nasal ; it may, however, in 
either species, slightly encroach upon the adjacent frontal 
hone. Its horizontal portion seems to be longer and more 
pointed in wild turkeys, than in the tame ones ; we will 
probably find numbers of exceptions to this rule, however, 
hut a still more constant character is to be found in the 
descending portion of the hone, which is evidently much 
longer, and more conspicuous in the former than it is in 
the latter species. 
Passing now to the fronto-interorbital region, it is the 
rule so far as I have examined, that the transverse diame- 
ter here is manifestly greater in the wild turkey than it is 
in the domesticated bird ; while, as I have already stated, 
the fore part of this region is more sunken in the former 
fowl. Posterior to the frontal area again, we find the 8 
Skulls of Wild and Domesticated Turkeys. 
parietal prominences better marked in wild turkeys than 
they are in tame ones. 
There are two other well-marked and comparable diame- 
ters upon this aspect of these skulls, but as they can 
he better appreciated upon the lateral view. I will defer 
their discussion until we come to consider that part of our 
subject. 
Let us now pass to the posterior views of these skulls, as 
shown in figures I) and E ; and, beginning from the top, 
we observe the more prominent parietal prominences in the 
Sisff.J?. 
S i*}. Si . 
Rearviews, life size, of the skulls of the wild (Fig, I)) and tame (Fig. E) 
turkeys. /, frontal bone ; p, parietal ; pf, postfrontal process. qj, quadrato- 
jugal ; q. quadrate ; fm, foramen magnum; and o. c., occipital comjy l<*. In 
both specimens the mandibles have been removed. 
wild turkey, over the evenly-rounded, corresponding region 
of the domesticated one. The principal feature, however, to 
he taken into consideration upon this aspect of the skull is, 
what I please to call here, the occipital area. By the occi- 
pital area I mean that space so definitely circumscribed 
upon this face of the cranium hy the bounding occipital 
ridge or line. In a great many birds the general form of 
this area, constitutes upon comparison a very good charac- 
ter. The rule here is, that in the tame turkey this area is 
decidedly more rounded than we ever find it in the wild Skulls of Wild and Domesticated Turkeys. 
9 
one, although we occasionally observe in the former that 
it assumes the cordate outline which, so far as my re- 
searches carry me, is invariably the case in M. g. mexicana. 
Little or no difference seems to distinguish the form of 
the occipital condyle among these fowls, for both in tame 
and wild turkeys, we find the notch at its middle point 
above to he deeply cleft in some cases, whereas in others it 
is barely perceptible. 
The occipital hone as a whole is thicker and apparently 
denser in the tame turkey than it is in the wild one, but as 
to the relative size of the brain cavities, I would prefer to 
measure a much larger series of skulls than I now have at 
my disposal. I would say, though, that little if any change 
has taken place in this particular ; and to accurately decide 
upon this important point, at least a hundred skulls for 
either species should be carefully measured, averaged and 
compared. If this ever he undertaken I simply predict that 
the result will show that the average capacity of the brain 
cavity will he found to be rather larger in the wild turkey 
than it is in the tame one, contrary to the usual rule fol- 
lowing domestication, I believe. 
Upon lateral view of these two typical skulls we find for 
comparison hut three points that demand our special con- 
sideration ; these are, the arch of the superior margin of 
the orbit; the depth of the parietal region; and, the inter- 
orbital septum (Figs. F and G). 
First, as to the arch of the superior margin of the orbit, 
we find this more elevated, and, as it were, more convexed 
in the wild than it is in the tame turkey, where this arc is 
depressed, long and shallow, and hut slightly raised above 
the plane of the frontal region. 
Another very well marked character and one rarely 
departed from, is the depth of the parietal region ; what I 
mean hv this is the distance measured on a median longi- 
tudinal line from the parietal prominences to the occipital 
ridge. This line is proportionately much shorter, and less 
horizontal in the wild turkey than it is in the domesticated 
one. By the aid of this character alone, I believe I could 
in a mixed collection of these two species of turkey, cor- 10 
Skulls of Wild and Domesticated Turkeys. 
rectly pick out the skulls of the vast majority that belonged 
to either kind. This difference is indicated by x in Figs. F 
and Gl. 
As to the condition of the interorbital septum I would 
say that, in all the specimens of M. g. mexicana, which I 
have examined, this bony plate is entire and of considera- 
ble thickness. I have found this to be the case in hut one 
instance in the series of skulls of the tame turkeys at my 
command, while in all the others of this latter species an 
irregular vacuity of some size exists in it (Fig. G, ios). 
Before passing to the consideration of the characters at 
the base of the skull, it would be as well to state that the 
skulls of wild turkeys differ as a rule from each other hut 
very little, and only to an extent due to the usual variance 
of each individual skull, whereas in a series of these speci- 
mens chosen from the domesticated turkey, we occasionally 
find a skull which in its several details more closely ap- 
proaches the average skull of the wild bird. 
Now at the base of the fekull I fail to find any constant 
differences in the basitemporal area of the two series, or in 
the quadrates; or the infraorbital bars; the palatines; 
the basis, basisphenoidal rostrum; the maxillo-palatines; 
or in the under side of the premaxillary, this last bone 
having already been alluded to. 
In the case of the pterygoids, however, I think it will as 
a rule be found, that in the wild species they are rather 
longer and slenderer than in the skull of the average tame 
turkey. Certainly it is so in the specimens before me. Al- 
though not showing any distinctive difference between the 
two varieties, for it appears to he equally well developed 
in both series. I have found the “ vomerine ossifications ” 
the most interesting features at the base of the skidl of 
these turkeys. 
According to the bibliography of Professor Elliott' Coues, 
Owen published in 1837 in P. Z. S., a paper entitled a “ Dis- 
section of the Head of the Common Turkey (Meleagris gallo- 
pavo)” comparing it at the same time with the head of the 
Cathartes aura. This contribution is not available to me 
at the present writing, and I am unable to say whether Skulls of Wild and Domesticated lurkeys 
11 
Fig. F.—Left lateral view of skull of M. g. mexicana, including the man dible. Life size and the same skull as shown in 
th.e other figures. 
Fig. G. -Left lateral view of the skull of a domesticated turkey; life size and the same one as in other figures—its man- 
dible is not drawn, pmx, premaxillary; n, nasal; eth, ethmoid; l, lacrymal: /, frontal; x. the length of parietal regiofi; so, su- 
praoccipital, sq, squamosal; ty, tympanic cavity; pf, post frontal process; rx, vomerine ossifications; d, dentary; pa. p, pos- 
terior angular process; i. a. p, internal angular process; ar, articular: a. angular; d, dentary; p, parietal; eo, exoccipital; q, 
quadrate; qi, quadrato-jugal; pg, pterygoid; j, jugal; ios, interorbital septum; pi, palatine; mx. maxillary. 
Tig-G. 
Fi9. F. 12 
Skulls of Wild and Domesticated Turkeys. 
Professor Owen passed any remarks in it upon the vomer or 
not.* I am not familiar with any other memoirs devoted 
especially to the anatomy of the Meleagris, and passing 
over the many recent text-books and memoirs referring to 
fowls, by the Parkers, Huxley, Claus, Bell and others, I 
take the statement of the author of the article “ Birds ” 
in the ninth edition of the Encyclopaedia Britannica as final 
authority on the subject, and he says that “ In the Gallin- 
aces, as in the desmognathous Rapaces, the vomer is single; 
in Pigeons and Sand-Grouse it is absent.'” 
Now the facts presented below are based upon careful dis- 
sections of mine of the heads of eleven turkeys in the flesh, 
of (the two kinds under consideration), with the view of de- 
termining the condition of the vomer, alone. Some of these 
investigations were made upon the heads while they were 
absolutely fresh; others had been a short time in alcohol; 
while still others were either parboiled, or had been sub- 
mitted to prolonged though careful maceration. In all the 
cases the structures were examined under a powerful lens. 
I found the usual plane of soft tissues extending from the 
entire anterior margin of the ethmoid to the posterior 
margin, of the cartilaginous nasal septum. Now when a 
bird possesses a single vomer, it is in this median plane of 
tissue that it is found, and for the common fowl, Professor 
W. K. Parker says, in his invaluable little treatise on the 
Morphology of the Skull, that, “ The maxillopalatine plates 
(mx. p.) are broader and reach nearly to the mid line, being 
separated partly by the nasal septum and partly by the 
small vomer, which is rounded in front, and split for a 
short distance behind. The forks of the vomer (v.) articulate 
with the inner and anterior points of the inner plates of the 
palatine bones, which lie side by side mesially, nearly con- 
cealing the rostrum,” (pp. 246, 247). Only in one turkey, 
*In forwarding my proof for correction, Dr. Conklin,the Journal’s Editor,did me the 
very great favor in sending with it the MSS. copy he had made of Prof. Owen’s 
article, herealluded to, for which I am exceedingly grateful. Upon reading this over 
1 And nothing in it respecting the vomer, or these vomerine ossifications, dealing as it 
does principally with the distribution of the olfactory nerves in the Vulture and 
Turkey, with the view of throwing light upon the question of the power of smell in 
the former bird, R. W. S. Skidls of Wild and Domesticated Turkeys. 
13 
and that an old domesticated gobbler, did I find any sem- 
blance of such a medium vomer, and in that specimen it 
was exceedingly small, close to the ethmoid, and composed 
of bone of the most elementary character. The aperture 
which fulfills the office of the “posterior nares” in a bird 
occurs in this locality, and the free edges of it extend from 
the anterior inner points of the palatines, to the correspond- 
ing apex of the maxillo-palatine, on either side. In the 
vast majority of the turkey heads which I examined, a 
delicate rod of bone is found in the soft tissues composing 
these free edges. So it will be seen that these two little 
rods of bone (Fig. C. vx.) extend from the anterior inner 
points of the palatines to the posterior apices of the max- 
illo-palatines, one of them on either side. Now it is with 
these “anterior inner points of the palatines,” that the 
vomer in a common fowl articulates, the bonelet 
extending forward, as already stated, as a diminutive 
median spine. This calls up some interesting questions, 
for say the little semi-ossified piece in the median plane of 
tissue—which I discovered only in one very old turkey, 
and in it, it did not fork behind and have the posterior 
extremities of the forks “ articulate with the anterior inner 
points of the palatines, ”—does not represent the vomer, hut 
that these little fully ossified rods, that I have just de- 
scribed, do; then we certainly have a singular departure in 
the turkey for a gallinaceous type, from the usual order of 
things. 
In a head of a wild turkey now before me, an old adult 
male, I found no median ossification at all, to represent a 
vomer, hut on the contrary both of these little rods are present 
and thoroughly ossified. As I write about this condition in 
the turkeys, my mind naturally reverts to what has been 
held for the Piei, and the organization in them of the corres- 
ponding parts; it has been said, as we know, that they 
have double vomers in adult life—but this was disputed by 
Garrod, (“Ibis” 1872 pp. 357-360), who claimed to have 
found a median vomer for the woodpecker. 
A careful comparison of the mandibles of these two se- 
ries of turkey skulls, fails to reveal to me any contestants 14 
Skulls of Wild and Domesticated Turkeys. 
of characters that could be relied upon to distinguish those 
belonging to the wild ones from those of the domesticated 
variety. 
I have also compared the ]iyoicl arches : the sclerotal 
plates of the eyeballs ; and other minor ossifications about 
the skull, and what I have just said in regard to the man- 
dibles, applies with equal force to them, there are no reli- 
able characters to distinguish them. 
This brings my comparisons of these two series of skulls 
to a close, and I will here complete my paper by a brief 
recapitulation of the constant characters which, so far as I 
have been able to ascertain, seem to distinguish the skull 
of a wild turkey from that of a domesticated one, the lat- 
ter being descended from domesticated stock of long stand- 
ing, and as free as possible from any mixture with the 
wild types. 
In drawing up this summary, I would have it distinctly 
understood that only the most constant differences have 
been selected, and exceptions even to these may occasionally 
be found among tame turkeys, where for some unknown 
cause, they seem, in certain individual cases, to revert 
again to the cranial structure of the wild species. 
These selected characters, will, however, show the ten- 
dency of the changes that are taking place, and are appar- 
ently up to the present time, typified in the skull of the 
tame turkey which 1 have chosen in the figures to illustrate 
them. I take it that these changes are still in somewhat 
of a transitional stage, and that eventually tame turkeys 
will differ quite widely from the wild ones. And that this 
difference will become much greater and more rapidly 
brought about when the breeding and selection of turkeys 
is more carefully looked into, with the view of introducing 
certain improvements in them., 
ANALYTICAL SUMMARY. 
1. As a rule, in adult specimens of M. g. mexicana, the 
posterior margins of the nasal bones indistinguishably fuse 
with the frontals; whereas, as a rule, in domesticated Skulls of Wild and Domesticated Turkeys. 
15 
turkeys their sutural traces persist with great distinctness 
throughout life. 
2. As a rule, in wild turkeys we find the cranio-frontal 
region more concaved, and wider across than it is in the 
tame varieties. 
3. The parietal prominences are apt to be more evident 
in M. g. mexicana than they are in the vast majority of 
domesticated turkeys; and the median, longitudinal line 
measured from these to the nearest point of the occipital 
ridge is longer in the tame varieties than it is in the wild 
birds. Generally this latter character is very 
striking and rarely departed from. 
4. The figure formed by the line which bounds the occipital 
area, is, as a rule, roughly semi-circular in a domesticated 
turkey, whereas in M. g. mexicana it is nearly always of a 
cordate outline, with the apex upwards. In the case of 
the tame turkeys I have found it to average one exception 
to this in every twelve birds; in the exception, the bound- 
ing line of the area made a cordate figure as in wild 
turkeys. 
5. Among the domesticated turkeys, the interorbital 
septum almost invariably is pierced by a large irregular 
vacuity; as a rule, this osseous plate is entire in wild ones. 
6. The descending process of a lacrymal bone is more apt 
to he longer in a wild turkey than in a tame one; and for 
the average the greater length is always in favor of the 
former species. 
if. In M. g. mexicana, the arch of the superior margin 
of the orbit is more decided than it is in the tame turkey, 
where the arc formed by this line is shallowed, and not so 
elevated. 
8. We find, as a rule, that the pterygoid bones are rather 
longer and more slender in wild turkeys than they are 
among the tame ones. 
9. At the occipital region of the skull, the osseous struc- 
tures are denser and thicker in the tame varieties of tur- 
keys ; and, as a whole, the skull is smoother, with its 
salient apophysis less pronounced in them than they are in 
the wild types. There is a certain delicacy and lightness, 16 
Skulls of Wild and Domesticated Turkeys. 
very difficult to describe, that stamps the skull of a wild 
turkey, and at once distinguishes it from any typical skull 
of a tame one. 
10. I have predicted that the average size of the brain 
cavity-will be found to be smaller and of a less capacity in a 
tame turkey than it is in the wild one. In the case of this 
class of the domesticated animals, this would seem to be 
no more than natural, for the domestication of the turkey 
has not been of such a nature as to develop its brain mass 
through the influences of a species of education ; its long 
contact with man has taught it nothing—quite the con- 
trary, for the bird has been almost entirely relieved from 
the responsibility of using its wits to obtain its food, or to 
guard against danger to itself. These factors are still in 
operation in the case of the wild types, and the advance of 
civilization has tended to sharpen them. 
From this point of view then, I would say, that men- 
tally the average wild turkey is stronger than the average 
domesticated one, and I believe it will be found that in all 
these long years, the above influences have affected the 
size of the brain-mass for the latter species in the way 
above indicated, and perhaps it may be possible some day 
to appreciate this difference. Perhaps, too, there may 
have been also a slight tendency on the part of the brain of 
the wild turkey to increase in size, owing to the demands 
made upon its functions due to the influences of man’s 
nearer approach, and the necessity of greater mental activ- 
ity in consequence.