or THE CEEEBEIJM OF THE QHADEUMANA. 
195 
more deeply cut, the hippocampus minor more prominent, and the posterior cornu 
patent to a greater extent. 
As has been already pointed out, from an examination of vertical sections of skulls, 
it is among members of this family that the occipital region of the cerebrum attains its 
greatest, and also, as far as the Apes properly so called are concerned, its least develop' 
ment ; the first in CJirysotJirix, one of the lowest, and the last in Mycetes, the genus 
usually placed at the head of the family. It is remarkable, also, that among the Catar- 
rhina, as estimated by the same means, the backward development of the cerebrum, in 
relation to the cerebellum, appears to coincide "with the order in which these animals 
are zoologically arranged, being least among the anthropoid Apes, and attaining its 
maximum in the Cynocephali. 
Family 3. Strejysirrhina. 
Most of the descriptions and figures of the brains of members of this family hitherto 
published are unsatisfactory. For example, that given by Tiedemann* of Lemur mongoz, 
though evidently drawn with great accuracy and care, represents a brain the form of 
which has been considerably altered by hardening in spirit. The same objection applies, 
but even more strongly, to the delineations of the brain of Stenops given by VROLixf 
and by Schroeder van der KolkJ. That of Tarskis, in the admirable memoir of 
Burmeister §, may perhaps be excepted. 
Having, therefore, lately had an opportunity of dissecting a Lemur in a fresh con- 
dition, I have thought it desirable to give a new figure of the external characters of the 
brain. The view of the upper surface (Plate HI. fig. 11) was drawn after the removal 
of the skull-cap, while the brain was still in the head; the other two (Plate III. 
figs. 12 & 13) immediately after it was taken out, and with the assistance of a cast of 
the Ulterior of the cranium. After the brain had been a fortnight in spirit, the hemi- 
spheres had lost one-fifth of their length, together with their characteristic outline, and 
had left about half of the cerebellum uncovered. 
Lemur nigrifrons, Geoff. [L. mongoz, Linn.!). — After removing the upper portion of 
the skull by a horizontal incision, and then taking away the dura mater, the surface of 
the encephalon was exposed. The part brought into view consisted of the cerebral 
hemispheres, with a small portion of the olfactory lobes projecting in front, and of the 
cerebellum behind. The general outline of the two cerebral hemispheres presented an 
oval figure, very narrow in front and broad behind, where it was deeply indented in the 
middle line. On looking directly down upon the centre of this oval, the portion of the 
cerebellum visible was part of the upper surface of the superior vermis, chiefly exposed 
by the divergence of the posterior apices of the cerebral hemispheres, and a very narrow 
* Op. cit. tab. iv. figs. 1, 2, 3, 4. 
t Bijdrage tot de Anatomie van den Stenops KuTcang. Leiden, 1841. 
J Nieuwe Verband. der 1® Klasse v. h. Eon. Nederlandscbe Inst. 1843. 
§ Beitrage zur naberen Kenntniss der Gattung Tarsius. Berlin, 1846. 
2 c 2 
