ie«. 



^im, 



' ^^ves 



> 



to 



lis 



^liiio^ 



tbr 



St 



""^^ i^ it. 



-•■'\? to 



one might 



^? )L 



diff, 



acaci 



ie 



qiiestion 

 from ttat 



il forms of 

 uint to tlie 

 » distinct, 

 [lee and fill 



« • 



remaining 



-:. A few 

 es, of the 



icrcrmss in 



Terres of 

 links 



11]^ 



^parated ! 

 1 pale 



on- 



id some 



IS wliicli 



pability 

 against 



•sti tbey 



liistorj'j 

 •ecei^t, 



1 



u 





iiieu 



tar/ 



1 



» 





V 

 ^ 



Ch. xliii.] 



CEREBRAL COXEORMATION. 



485 



nature of tlie record with wliicli tlie geologist lias to deal/^ 

 To one wlio is not aware of the extreme imperfection of this 



missm 



^ lificance ; but to those who are thoroughly imbued 

 with a deep sense of the defectiveness of the archives^ each 

 new form rescued from oblivion is an earnest of the former 

 existence of hundreds of species^ the greater part of which are 

 irrecoverably lost. 



Progressive development in the cerehral conformation of the 

 vertehrata^ inchiding man. — I have already remarked when 

 combating the notion that man in his corporeal structure has 

 arrived at a fixed and stationary condition, that w^e have 

 no right to make such an assumption, until we have acquired 



a more definite idea of 



number of centuries which it 



took for the most marked of the human races to diverge, in 

 difPerent directions, so far from a common type. The rate of 

 change generally in the animal and vegetable kingdoms is 



9 



slow and insensible, and naturalists have never yet witnessed 

 the formation of any one of the wild races which they regard 

 as mere geographical varieties. They know not how^ many 

 thousand generations it may have required to produce such 

 changes ; but we cannot infer in their case, or in that of man, 

 that the era of the immutability of species has arrived. If 

 the organisation of man has been modified in comparatively 

 modern times, it is probably, as before hinted, in his cerebral 



Liniiseus declared 



ition has been maniiested. 



that he could not distinguish man 



generically from the ape, and Professor Owen has spoken of 

 the ' all-pervading similitu.de of structure — every tooth, every 

 bone, being strictly homologous' — yet the same great anato- 



man 



en- 



titling him to be placed in a sub-class apart from all the 

 other mammalia. He has proposed a new classification of 

 the highest division of the vertebra ta with reference to the 

 characters of their brain, and its greater or less resemblance, 

 in volume and structure, to that of man. Some have ob- 

 jected, not perhaps without reason, that everv such attempt 



"^ See above, Vol. I. p. 318 



\ 



