Chap. YII.] TEE RACES OF MAN. ' 219 



while in other genera, as in Cercopithecus, most of the 

 species can be determined with certainty. In the Ameri- 

 can genus Cebns, the various forms are ranked by some 

 naturalists as species, by others as mere geographical 

 races. Now, if numerous specimens of Cebus were col- 

 lected from all parts of South America, and those forms 

 which at present appear 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 kingdom, 18 which we cannot avoid naming as 

 species, but which are connected together, independently 

 of intercrossing, 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 deserve 

 so high a rank. Now, if we reflect on the weighty argu- 

 ments, 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-species " might 

 here be used with much propriety. But from long habit 

 the terni "race" will perhaps always be employed. The 

 choice of terms is only so far important as it is highly de- 

 sirable to use, as far as that may be possible, the same 

 terms for the same degrees of difference. Unfortunately, 

 this is rarely possible ; for within the same family the 

 larger genera generally include closely-allied forms, which 

 can be distinguished only with much difficulty, while the 

 smaller genera include forms that are perfectly distinct ; 



18 Prof. Nageli 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 Composites 

 of Xorth America. 



