Dr Morton on Hybrid Animals arid Plants. 263 



two distinct species of animals, are incapable of reproducing 

 their kind ; thus making hybridity the test of specific cha- 

 racter. It follows, according to this supposed law of nature, 

 that if mankind embraced several species, the intermixture 

 of these would go no further than to produce a steril hybrid 

 variety. But since all the races are capable of producing, 

 with each other, a progeny more or less fertile, it is inferred 

 that they must all belong to one and the same species. This 

 is the question at issue. 



It may, at first view, appear superfluous to go over the 

 whole ground of inquiry ; but apart from its Ethnographic 

 relations, it is my wish to call attention to a branch of science 

 that has hitherto been singularly neglected, and perhaps 

 more so than any other. Having sought in vain for some 

 collective exposition of its details, I was at length induced 

 to examine them for myself; and in now giving them publi- 

 city, I respectfully solicit, from practical observers, any 

 authenticated examples of an analogous kind, that may not 

 be embraced in this memoir. 



We shall merely further premise, that naturalists have 

 differed as to the import of the word species ; but we know of 

 no better definition than that which is expressed by " sepa- 

 rate origin and distinctness of race, evinced by the constant 

 transmission of some characteristic peculiarity of organiza- 

 tion.*' The term race has been indefinitely and convenient- 

 ly used in those instances in which it is difiicult to decide 

 whether an individual of any tribe of plants or animals, is a 

 distinct species, or only a variety of some other species. 

 Races are properly successions of individuals propagated 

 from any given stock ; and we agree with the learned Dr 

 Prichard. from whom we cite these definitions, that when 

 races can be proved to possess certain primordial distinctions, 

 which have been transmitted unbroken, they should be re- 

 garded as true species.* 



* Researches into the Physical History of Mankind, 3d Edit., pp. 105, 109. 

 — For some highly interesting views of this question, and their practical ap- 

 plication, see Prof, llaldeman's Enumeration of Fresh Water Mollusca, in Bos- 

 ton Jour, of Nat. Hist., 1844. Further researches into Ethnographic affinities, 



