110 MR. FLOWER ON THE BRAIN OF THE JAVAN LORIS. 
Apes: the cerebrum is so short as to leave almost the whole of the cerebellum 
uncovered, and the Sylvian fissure is almost obliterated. On these grounds alone we 
might be induced to place these orders far away from each other, in a system of classi- 
fication founded mainly on cerebral organization, if the fact of the persistence of the 
primatial type of convolution upon a degraded configuration of brain in the Lemurs did 
not warn us that it is possible that the Cheiroptera, and perhaps the Insectivora also, 
may form a group presenting a still lower degree of development (characterized by still 
shorter hemispheres) of the same high type, and that therefore, in the absence of any 
knowledge of what the surface-markings of the hemispheres of the Cheiroptera would 
be if developed, there scarcely seems sufficient justification for removing them, on the 
score of their cerebral organization alone, from the position assigned to them on other 
grounds by Linneus, Cuvier, and a large majority of systematic zoologists. It may 
be, perhaps, that we shall find in the simpler brains of this lower group a common 
form by means of which the more completely developed and specialized cerebral 
organs of the Carnivora and the Quadrumana are united, and through which, instead 
of through any direct link, their affinities are to be read. At all events, it cannot be 
doubted that more searching comparisons of the form and the convolutions of the 
brains of different groups of Mammalia, conducted on such a system as that so suc- 
cessfully pursued in one group by M. Gratiolet, will throw much light upon the mutual 
relation of different members of the class, and I trust that these few observations upon 
a very interesting form may be accepted by the Society as a small contribution towards 
this desirable end. 
Note.—May 1862. The recent examination of the brain of a specimen belonging to 
the genus Pithecia (Proceedings of the Zoological Society, Dec. 9, 1862) has led to a 
different determination of the sulci of the posterior part of the inner face of the hemi- 
sphere to that given above and in the author’s paper ‘‘ On the Posterior Lobes of the 
Quadrumana” (Phil. Trans. 1852). The sulcus marked k, in figs. 4, 7, & 10 (Stenops, 
Lemur, and Nyctipithecus), which was supposed to represent the occipito-parietal of the 
higher Quadrumana, is more probably the upper branch of the posteriorly bifurcating 
calcarine, because (in Nyctipithecus, without doubt) it is homologous to a small sulcus 
which in Pithecia coexists with a true occipito-parietal descending from the upper 
margin of the internal face of the hemisphere and, as in all except the highest 
Quadrumana, not extending so low as to join the calcarine (Joc. cit. fig. 4). All trace 
of this sulcus is absent in the smaller Platyrhine Monkeys and Lemurs. 
