278 BRANCH VKRTEBRATA. 



five races, authors disagree. 80 that, although there are 

 some differences of structure and great diversity in the 

 texture of the skin and the character of the hair of 

 mankind in various localities, yet in the same nation 

 there are similar varieties; and as marked diversities 

 have repeatedly been observed in a single species of the 

 domestic animals. We therefore agree with Dr. Prichard 

 ''that no other differences occur than may fairly be 

 attributed to the differences of external circumstances ; 

 and hence it may safely be concluded that the different 

 races are all members of the same family, and the off- 

 spring of one common stock." 



