198 THE DESCENT OP MAN. 



To which I reply, firstly, that whether this assertion be true of 

 false, it has nothing whatever to do with the proposition enun- 

 ciated in 'Man's Place in Nature,' which refers not to the develop- 

 ment of the convolutions alone, but to the structure of the whole 

 brain. If Professor Bischoff had taken the trouble to refer to p. 

 96 of the work he criticizes, in fact, he would have found the fol- 

 lowing 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 between 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 Le- 

 "murs. Every Lemur which has yet been examined, in fact, has 

 "its cerebellum 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 contrary, has its 

 "cerebellum entirely hidden, posteriorly, by the cerebral lobes, and 

 "possesses a large posterior cornu with a well-developed hippo- 

 "campus 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 discovery of the 

 relatively small development of the posterior lobes in the Siamang 

 and in the Howling monkey. Notwithstanding 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 nat- 

 ural place, as Professor Bischoff most unaccountably does, vre 

 write the series of animals he has chosen to mention as follows: 

 Homo, Pithecus, Troglodytes, Hylobates, Semnopithecus, Cynoce- 

 phalus, Cercopithecus, Macacus, Cebus, Callithrlx, Hapale, Lemur, 

 Stenops, I venture to reaffirm that the great break in this series 

 lies between Hapale and Lemur, and that this break is consid- 

 erably greater than that between any other two terms of tliat 

 series. Professor Bischoff ignores the fact that long before he 

 wrote, Gratiolet had suggested the separation of the Lemurs from 

 the other Primates on the very ground of the difference in their 

 cerebral characters; and that Professor Flower had made the fol- 

 lowing obervations in the course of his description of the brain of 

 the Javan Loris." 



"And it is especially remarkable that, in the development of the 

 "posterior lobes, there is no approximation to the Lemurine, short 

 "hemisphered, brain, in those monkeys which are commonly sup- 



'5 'Transactions of the Zoological Society,' vol. v. 1862. 



