NOTES ON THE BRAIN* 
BURT G. WILDER, M.D. 
/ADDITIONAL Case of Independence of the Paroccipital 
Fissure.—In my recent paper “ On the Paroccipital Fis- 
sure” (76, 308), I gave the result of a tabulation of the relia- 
ble specimens and figures accessible to me as follows: 
among 43 hemicerebrums, the parietal and paroccipital are 
continuous in 21 and separate in 22. Since the publication 
of that paper I have prepared the perfectly fresh brain of a 
negro child (No. 1834 of the Museum of Cornell Uni- 
versity) that died at birth. In addition to other interest- 
ing facts which I hope to present at a future meeting, this 
brain has the two fissures totally independent on the right 
and barely united by a very shallow junction on the left. 
Even, then, if the latter be admitted as technically an ex- 
ample of continuity, the totals are now 22 unions to 23 
cases of independence.1 This brain, it will be seen, also illus- 
trates Ecker’s generalization, that the interruption of his 
“ interparietal,” which he regards as normally a continuous 
fissure, occurs more frequently on the right side. The in- 
terruption has now been observed on 10 right sides and 
only 4 left, while the junction occurs on 11 left and only 6 
* Read at the meeting of the Am. Neurological Association, July, 1886. 
1 Since this paper was read Dr. C. L. Dana has kindly put in my hands his 
notes and diagrams of twelve hemicerebrums in his possession : in seven the 
parietal and paroccipital are connected, how deeply not ascertained ; in one the 
junction is by a “very shallow depression ” ; in the other four, the separation 
is complete. The paroccipital is likewise wholly independent on both sides of 
a second brain of a negro child at birth (No. 2041, M. C. U.) which was re- 
moved by Dr. Formad and sent to Dr. C. K. Mills who generously turned it 
over to me. Admitting that Dana’s case of shallow union should be placed 
with the series of continuity, the totals are now thirty cases of continuity to 
twenty-nine of complete independence. 
Reprinted from the Journal of Nervous and Mental Disease, Vol. xiii., 
No. 8, 1886. 2 
BURT G. WILDER. 
right. It remains to ascertain the cause and significance of 
this difference between the two sides. As stated by me in 
1873 (11, 219) a fissure represents more cinerea than a super- 
ficial gyral surface of equal width, so we may associate this 
greater frequency of cinereal increase in a limited locality 
with the commonly superior weight and activity of the en- 
tire left hemicerebrum. 
An Ental Correlative of the Occipital Fissure in the Early 
Foetus.—As shown by the exhibited photograph and fig- 
ure, in a foetus (No. 1816 in Mus. of Cornell University) 
estimated to be about four months old, there is, immediately 
opposite the somewhat deep occipital fissure, a distinct ele- 
vation of the mesal wall of the postcornu, just dorso-ceph- 
alad of the calcar. The wall here is but little thinner than 
elsewhere, so that there is the appearance of a wrinkle or 
fold in the entire thickness as with the calcar. After the 
observation was made, this spring, I noticed that a similar 
elevation corresponding with the occipital fissure is figured by 
Tiedemann (PI. IX., Fig. 2), who, however, does not mention 
it in the text, and that an ental elevation corresponding to 
the occipital fissure is mentioned by Mihalkovics (146), who 
implies that it is mentioned by His. Although I have 
not had an opportunity of looking in other foetal brains, 
the distinctness of the elevation in the example here de- 
scribed, leads me to anticipate that it will be found a con- 
stant feature of the early foetal brain. 
Besides its constancy in the foetus, three other questions 
arise in connection with it: 1. Does it persist in the adult ? 
2. If so, has it been already recognized? 3. How shall it be 
designated ? 
None of these questions can be answered satisfactorily 
with the information now at hand. At present it seems 
probable that with some brains the general thickening of 
the postcornual parietes renders this early ridge hardly, 
if at all, distinguishable; but that in others it may be 
recognized as the oblique elevation dorso-cephalad of the 
calcar, which was called by Henle (p. 168, Figs. 91-93) 
bulbus cornu posterioris, by Quain (11, 346) bulb of the 
posterior cornu, and by me, in ignorance of the foregoing, NOTES ON THE BRAIN. 
3 
eminentia splenialis (58, 234, 273, Fig. 44). If it should 
prove to be distinct from the postcornual bulb, it may well 
be named eminentia occipitalis. 
Meantime, its relation to the occipital fissure in the foetus 
justifies the inclusion of the occipital among the total fis- 
sures, or foldings of the entire thickness of the coelian par- 
ietes, as distinguished from cortex fissures, or depressions 
reaching to a certain depth only. The other such cases of 
correlation between ental elevations and fissures are : calcar 
and calcarine fissure; hippocamp and hippocampal fissure; 
eminentia collateralis and collateral fissure; striatum and 
Sylvian fissure. In addition, the following are cases of 
structural correlation although the part does not project 
into the encephalocoele as an elevation: olfactory lobe and 
fissure ; amygdala and amygdaline fissure, or postrhinal fis- 
sure. See my paper (66). 
The Foetal Extension of the Proplex to the End of the Post- 
cornu.—In the adult the proplex or proccelian (lateral) por- 
tion of the prosoplex is practically confined to the cella and 
medicornu, with occasionally a pointed projection into the 
other cornus, as represented in my preparation, No. —, 
M. C. U. Since, however, the early hemicerebrum is nearly 
accurately filled by the plexus, it might be expected that in- 
termediate stages would be found on careful examination. 
In the photograph here shown, enlarged about two diame- 
ters from a horizontal section of a foetal brain estimated at 
months, the plexus is seen to extend to the end of 
the postcornu. Most of the postcornual portion, however, 
seems thinner and less substantial than the rest, as if in 
process of atrophy. Whether it comes off or simply shrinks 
cannot be ascertained as yet. There were indications of a 
similar precornual prolongation. 
Points Illustrated by the Transection of a Foetal Brain.— 
As shown in the exhibited photograph, a transection of 
the brain of a foetus, No. 1816, estimated at four months 
(the same which presented the ental correlative of the oc- 
cipital fissure), exhibits several features which are morpho- 
logically suggestive. 
1. The medicommissure is perfectly ‘distinct and well 
preserved. 4 
BURT G. WILDER. 
2. The procceles (lateral ventricles) are higher than wide, 
and half their height lies dorsad of the level of the callosum. 
3. The caudatum (caudate portion of the striatum) forms 
a marked projection of the lateral wall. 
4. The fornix at this level occupies about one third of the 
entire width of the cerebrum, whereas in the adult it measures 
not more than one fifth and probably more nearly one seventh. 
5. The fimbria, constituting the margin of the fornix, 
reaches the sulcus limitans, which demarcates the thalamus 
from the striatum, the diencephal from the prosencephal. 
In other words, each hemifornix is equal in width to the 
corresponding thalamus. 
6. As corollaries to the preceding : (A) the dorsal surface 
of the thalamus is wholly pial, with no endymal portion as 
in the adult; (B) the thalamus does not, in any sense, enter 
into the composition of the procoelian floor. This point is 
discussed at some length in my paper, 56, pp. 460, 461. 
It will be seen that most of the foregoing points are more 
or less distinctly related to the increase in width of the en- 
tire brain, and specifically to the lateral extension of the 
thalami during the later stages of foetal life. 
The non-appearance of the thalamus in the proccele, and, 
the concomitant narrowness of the rima, are also significant, 
because it is the permanent condition in all other mammals 
with the possible exception of some other primates. Hence 
these facts bear upon the important question as to the nature, 
extent, and significance of human or primatial peculiarities. 
BIBLIOGRAPHY. 
Mihalkovics, V. von : Entwicklungsgeschichte des Gehirns, etc. Q., 195, 7 
plates. Leipzig, 1877. 
Wilder, B. G. : 11. The outer cerebral fissures of mammalia (especially of 
the carnivora), and the limits of their homologies. Am. Assoc. Proc., xxii., 
1873 (pt. 2), pp. 214-234 ; 19 figures. 
56. Methods of studying the brain. The “ Cartwright Lectures ” for 
1884. JV. Y. Med. Jour., xxxix., 1884, pp. 141-148, 177-183, 205-209, 233- 
237. 373-377. 457-461, 513-516, 653-656; xl., 113-116 ; 64 figs. Abstracts in 
N. Y. Med. Record, xxv., 1884, pp. 141-143, 197-199, 225-227, 365-367, 449, 
450, 545, 546. 
60. On two little known cerebral fissures, with suggestions as to fissural 
and gyral names. Amer. Neurol. Trans. ; Jour. Nerv. and Ment. Dis., xii., 
350-352, July, 1885. 
76. The Paroccipital, a newly recognized fissural integer. Jour. Nerv. 
and Ment. Dis., xiii., pp. 301-315 ; 5 figs. ; June, 1886.