488 ON THE RELATIONS OF MAN WITH THE LOWER ANIMALS 
in determining in what manner the cerebeNum becomes covered, we 
too exclusively attend to the posterior elongation of the cerebral 
hemispheres, while the varying size of the cerebellum itself ought to be 
taken into account. On comparing the perpendicular section of the 
brain of the new-born child (pl. ii., fig. 3.) with fig. 1, the brain of the 
three-year-old chimpanzee, and with fig. 2, that of the orang of a like 
age, it is at once apparent that the cerebellum of the orang, and 
especially of the chimpanzee, is much larger than that of the child ; so 
that, supposing one could place the cerebellum of the chimpanzee 
behind the medulla oblongata of the child, it would be even less 
covered. 
“In fact, the distance from the anterior edge of the most anterior 
part of the cerebellum, close to the corpora quadrigemina, to its 
posterior margin, measures, in the chimpanzee, 38 mm. ; in the orang, 
35 mm.; in the child, 22 mm. If we compare the measurements with 
the whole distance from the anterior to the posterior lobe of the cere- 
brum, we obtain, according to measurements taken by the first named 
of us,— 
Chimpanzee, 8: 101 mm. = 1: 2°66, 
Orang, 35: 96 = T+ 2°74. 
Human child, 22: 96 = 1: 4°36. 
Adult man, . 502 157 SPs 34. 
“ Hence, it is clear 1°, that the cerebellum in the Chimpanzee and 
in the Orang are proportionally larger than in man; 2°, that the Orang 
in this respect approaches man more closely than does the Chimpanzee.” 
—* Anatomical Investigation,” &c., 1. c. pp. 265-7. 
The authors go on to remark that the same large proportion of the 
cerebellum to the cerebrum is characteristic of the lower Mammalia, as 
Scemmering had already observed, and that, consequently, the uncover- 
edness of the cerebellum arises as much from the disproportionately 
large size of the latter, as from the defect of the posterior lobe of the 
cerebrum. They further show that the human cerebelium is pro- 
portionally still smaller in a six-months’ foetus (1 : 4:7); and that, while 
in the adult the cerebellum has more than double the size it had inthe 
new-born child (50 : 22), the cerebrum of the adult is only 14 times as 
large in the adult as in the new-born child (157: 96). At the same 
time the cerebellum attains its full size by the end of the third year— 
a fact which indicates very interestingly the relations of the cerebellum 
with the locomotive power. 
M. Gratiolet commences his description of the cerebral convolutions 
of man thus :— 
“The form of the human brain is well known. Its singular height, 
