MR. FLOWER ON THE BRAIN OF THE JAVAN LORIS. 109 



and Stenops respectively. Callithrix moloch, as figured by Gratiolet (fig. 11), has a 

 moderately extended Sylvian fissure, a well-marked antero-temporal and a distinct 

 angular sulcus, as in Lemur, while in the Douroucouli {Nyctipithecus triviryatus) there 

 is a Sylvian fissure much prolonged upwards and backwards, an antero-temporal, but 

 no angular sulcus, all of which characters are reproduced in Stenops. Thus the most 

 marked differences between the brains of Lemur and Stenops find their parallel in those 

 of two very nearly allied genera of another family. 



The cerebellum of Lemur nigrifrons appears to me to present marked characters of 

 inferiority as compared with the same part in the true Apes, especially in the large 

 relative proportion of the vermes, both median and lateral, as compared with the bodies 

 of the three divisions of this organ ; but, as before stated, Stenops does not present this 

 character in so marked a degree ; indeed I could perceive little essential difference 

 between the cerebellum of this animal and that of Hapale and the other small Monkeys ; 

 but my observations on this point do not agree with those of Vrolik, and may require 

 verification. 



Comparison of the Brains of Lemur and Stenops with those of the lower Mammalia. 



Having placed side by side with the brains of the animals now under review those 

 of some of the smaller Carnivora, as the Cat and the Kinkajou (Cercoleptes caudi- 

 volvidus), it becomes evident that these latter present a common family likeness to each 

 other in the character of their convolutions, and belong to a different type from that 

 on which the Lemurs and Monkeys are formed. In general shape they certainly are 

 approached by the Lemuridae, but in the arrangement of the sulci it is difficult to trace 

 any resemblance ; the nomenclature of the superficial parts of the hemisphere of the 

 one utterly fails us when we attempt to apply it to the other. In the Carnivora the 

 convolution surrounding the rudimentary Sylvian fissure is followed by two or three 

 more, one encircling the other, the upper one bounded by the margin of the hemi- 

 sphere. On the inner face the dissimilarity is equally striking, especially in the 

 absence of anything resembling the calcarine fissure (see fig. 12, inner face of the 

 right hemisphere of a cat's brain). Whether more critical researches, aided by a 

 careful study of the development of the convolutions, will hereafter enable us to trace 

 the homology between the parts marked off by such dissimilar patterns I cannot say ; 

 but no satisfactory solution of the problem has yet been offered. 



To turn to another group of animals with which the Lemurs are supposed to have 

 affinities, viz. the Cheiroptera, our difficulty is here greatly increased by the want of any 

 member of the order with a brain of sufficient size to possess sulci on its surface. In 

 a species of Pteropus I could trace none distinctly, and indeed it could scarcely be 

 expected when such markings are almost absent in the brain of a true Primate of even 

 larger size {Hapale). In general form the Bat's brain is far removed from that of the 



