268 THE DESCENT OF MAN 



the trouble to refer to p. 96 of the work lie criticises, in fact, 

 he would have found the following passage: "And it is a 

 remarkable circumstance that though, so far as our present 

 knowledge extends, there is one true structural break in the 

 series of forms of Simian brains, this hiatus does not lie be- 

 tween man and the manlike apes, but between the lower and 

 the lowest Simians, or, in other words, between the Old 

 and New World apes and monkeys and the Lemurs. Every 

 Lemur which has yet been examined, in fact, has its cerebel- 

 lum partially visible from above; and its posterior lobe, with 

 the contained posterior cornu and hippocampus minor, more 

 or less rudimentary. Every marmoset, American monkey, 

 Old World monkey, baboon, or manlike ape, on the con- 

 trary, has its cerebellum entirely hidden, posteriorly, by 

 the cerebral lobes, and possesses a large posterior cornu 

 with a well-developed hippocampus minor,' 



This statement was a strictly accurate account of what 

 was known when it was made; and'it does not appear to me 

 to be more than apparently weakened by the subsequent dis- 

 covery of the relatively small development of the posterior 

 lobes in the Siamang and in the Howling monkey. Not- 

 withstanding the exceptional brevity of the posterior lobes 

 in these two species, no one will pretend that their brains, 

 in the slightest degree, approach those of the Lemurs. And 

 if, instead of putting Hapale out of its natural place, as Prof. 

 Bischoff most unaccountably does, we write the series of ani- 

 mals he has chosen to mention as follows: Homo, Pithecus, 

 Troglodytes, Hylobates, Semnopithecus, Gynocephalus, Cerco- 



fiihecus, Macacus, Cebus, Callithrix, Jlapale, Lemur, Stenops, 

 venture to reaffirm that the great break in this series lies 

 between Hapale and Lemur, and that this break is consider- 

 ably greater than that between any other two terms of that 

 series. Prof. Bischoff ignores the fact that long before he 

 wrote, Grratiolet had suggested the separation cf the Lemurs 

 from the other Primates on the very ground of the difference 

 in their cerebral characters; and that Prof. Flower had made 

 the following observations in the course of his description of 

 the brain of the Javan Loris :" 



"And it is especially remarkable that, in the develop- 

 ment of the posterior lobes, there is no approximation to 

 the Lemurine, short-hemisphered brain, in tnose monkeys 

 which are commonly supposed to approach this family lu 



« "Transaotions of the Zoological Societj," vol. v., 1862. 



