Chap. VII. THE RACES OF MAN. 227 



take the description of a group of highly varying 

 organisms, has encountered cases (I speak after ex- 

 perience) precisely like that of man ; and if of a cautious 

 disposition, he will end by uniting all the forms which 

 graduate into each other as a single species ; for he will 

 say to himself that he has no right to give names to 

 objects which he cannot define. Cases of this kind occur 

 in the Order which includes man, namely in certain 

 genera of monkeys ; whilst in other genera, as in Cerco- 

 pithecus, most of the species can be determined with 

 certainty. In the American genus Cebus, the various 

 forms are ranked by some naturalists as species, by 

 others as mere geographical races. Now if numerous 

 specimens of Cebus were collected from all parts of 

 South America, and those forms which at present ap- 

 pear to be specifically distinct, were found to graduate 

 into each other by close steps, they would be ranked by 

 most naturalists as mere varieties or races ; and thus the 

 greater number of naturalists have acted with respect 

 to the races of man. Nevertheless it must be confessed 

 that there are forms, at least in the vegetable king- 

 dom, 18 which we cannot avoid naming as species, but 

 which are connected together, independently of inter- 

 crossing, by numberless gradations. 



Some naturalists have lately employed the term 

 " sub-species " to designate forms which possess many of 

 the characteristics of true species, but which hardly de- 

 serve so high a rank. Now if we reflect on the weighty 

 arguments, above given, for raising the races of man to 

 the dignity of species, and the insuperable difficulties 

 on the other side in defining them, the term " sub- 



18 Prof. N'ageli has carefully described several striking cases in his 

 ' Botanische Mittheilungen,' B. ii. 1866, s. 294-369. Prof. Asa Gray 

 has made analogous remarks on some intermediate forms in the Com- 

 posite of N. America. 



Q 2 



