42 GORILLAS AND CHIMPANZEES 



question of making two species of them, or assigning 

 them to the same. 



The skeletons, as we have noted, are the same in 

 form, size and proportion. Their muscular, nervous, 

 and veinous systems are the same, except a slight 

 structural variation in the genital organs of the 

 males, and the degree of mobility in certain facial 

 muscles. The character of their food, and the mode 

 of eating it, are the same in each. In captivity they 

 appear to regard each other as one of their own 

 kind, but whether they mate or not remains to be 

 learned. 



Such is the sum of the likenesses and differences 

 between the two extreme types of this genus ; but 

 with so many points in common, and so few in which 

 they differ, it is a matter of serious doubt whether 

 they can be said to constitute two distinct species, 

 or only two marked varieties of a common species. 

 This doubt is further emphasised by the fact that all 

 the way between these two extremes are many gra- 

 dations of intermediate types, so that it is next to 

 impossible to say where one ends and the other 

 begins. 



In view of all these facts, I believe them to be two 

 well-defined varieties of the same species ; they are 

 the white man and the negro of a common stock. 

 They are the patrician and plebeian of one race, or 

 the nobility and yeomanry of one tribe. They are 

 like different phases of the same moon. The kulu- 

 kamba is simply a high order of chimpanzee. 



It is quite true that two varieties of one species 



