482 ON THE RELATIONS OF MAN WITH THE LOWER ANIMALS 
mann not only described but figured the posterior cornu of the lateral 
ventricle in the Sze (Tab. 2°, Fig. 37), as “e. scrobiculus parvus loco 
cornu posterioris ;” and when giving an account of the brain of the seal 
(Tab. 3°), he says: “e. cornu descendens s. medium. Preterea cornu 
posterioris vestigium occurrit.” 
Tiedemann’s statements are confirmed by every authoritative writer 
since his time. According to Cuvier! (Lecons, T. iii., p. 103), “ the an- 
terior or lateral ventricles-possess a digital cavity [posterior cornu] only in 
manandtheapes. This part exists in no other mammifer. Its presence 
depends on that of the posterior lobes. In the seals and dolphins alone, 
in which the posterior part of the hemisphere is considerable, the lateral 
ventricle, at the point where it descends into the temporal tuberosity, 
bends a little backwards, thus exhibiting a sort of vestige of the digital 
cavity of the human brain.” 
Vrolik (Art. Quadrumana, Todd's Cyclopedia), though he carefully 
enumerates the differences observable between the brains of the Quadru- 
mana and that of man, does not think of asserting the absence of the 
posterior cornu. And lastly, Schroeder van der Kolk and Vrolik (op. 
cit., p. 271), though they particularly note that “the lateral ventricle 
is distinguished from that of man by the very defective proportions of 
the posterior cornu, wherein only a stripe is visible as an indication of 
the hippocampus minor;” yet the figure 4 in their second Plate shows 
that this posterior cornu is a perfectly distinct and unmistakable struc- 
ture, quite as large as it often is in man. It is the more remarkable 
that Professor Owen should have overlooked the explicit statement and 
figure of these authors, as it is quite obvious, on comparison of the 
figures, that his wood-cut of the brain of a Chimpanzee (I. c., p. 19), is 
a reduced copy of the second figure of Messrs. Schrceder van der Kolk 
and Vrolik’s first Plate. 
As M. Gratiolet (1. c., p. 18), however, is careful to remark, “ unfor- 
tunately the brain which they have taken as a model was greatly altered 
(profondément affraissé), whence the general form of the brain is given 
in these plates in a manner which is altogether incorrect.” Indeed, it 
is perfectly obvious, from a comparison of a section of the skull of the 
Chimpanzee with these figures, that such is the case ; and it is greatly to 
be regretted that so inadequate a figure should have been taken as a 
typical representation of the Chimpanzee’s brain. 
3. The Hippocampus minor.—But even supposing that the posterior 
cornu of the lateral ventricle and its appendage, the hippocampus minor, 
were absent in the apes, and “ peculiar to the genus Homo,” what 
classificatory value would the distinction possess? This, of course, 
' Leuret, Longet, and Stannius, agree with or, perhaps, only repeat Cuvier. 
