202 THE DESCENT OP MAN. 



sylvian fissure and the deep calcarine fissure, only a very shallow 

 anterotemporal fissure (scissure parallgle of Gratiolet). 



Now this fact, taken together with the circumstance that the 

 anterotemporal sulcus is present in such Platyrhini as the Sai- 

 miri, which present mere traces of sulci on the anterior half of 

 the exterior of the cerebral hemispheres, or none at all, undoubt- 

 edly, so far as it goes, affords fair evidence in favor of Gratiolet's 

 hypothesis, that the posterior sulci appear before the anterior, in 

 the brains of the Platyrhini. But, it by no means follows, that 

 the rule which may hold good for the Platyrhini extends to the 

 Catarhini. We have no information whatever respecting the de- 

 velopment of the brain in the Cynomorpha; and, as regards the 

 Anthropomorpha, nothing but the account of the brain of the 

 Gibbon, near birth, already referred to. At the present moment, 

 there is not a shadow of evidence to show that the sulci of a chim- 

 panzee's, or orang's, brain do not appear in the same order as a 

 man's. 



Gratiolet opens his preface with the aphorism, "II est dangereux 

 "dans les sciences de conclure trop vite." I fear he must have for- 

 gotten this sound maxim by the time he had reached the discus- 

 sion of the differences between men and apes, in the body of his 

 work. No doubt, the excellent author of one of the most re- 

 markable contributions to the just understanding of the mammal- 

 ian brain which has ever been made, would have been the first 

 to admit the insufficiency of his data had he lived to profit by the 

 advance of inquiry. The misfortune is that his conclusions have 

 been employed by persons incompetent to appreciate their foun- 

 dation, as arguments in favor of obscurantism.'" 



But it is important to remark that, whether Gratiolet was right 

 or wrong in his hypothesis respecting the relative order of appear- 

 ance of the temporal and frontal sulci, the fact remains; that, be- 

 fore either temporal or frontal sulci, appear, the foetal brain of 

 man presents characters which are found only in the lowest group 

 of the Primates (leaving out the Lemurs) ; and that this is ex- 

 actly what we should expect to be the case, if man has resulted 

 from the gradual modification of the same form as that from 

 which the other Primates have sprung. 



»'■ For example, M. I'Abbe Lecomte in his terrible pamphlet 'Le Dar- 

 winisme et I'origine de I'Homme,' 1S73. 



