SPECIES AND RACE. 29 



arise and disappear in the course of time, or which may be 

 found in several generations of the same stock. The argu- 

 ment, on the other hand, for difference of species in any case, 

 has but little to support it, if the variation of the respective 

 types, leading to an alteration of type, cannot be demonstrated. 

 The proof would only be perfect if we succeeded in positively 

 demonstrating the immutability of the pure types after they 

 have for a sufficiently long time been subjected to the most 

 various external influences, and have given rise to a relatively 

 large number of mongrels of these types and their varieties, to 

 establish the fact that the hybrids ultimately revert to their 

 respective original types. If they prove prolific between them- 

 selves without the mongrels exhibiting a tendency to reversion, 

 the fixity and, consequently, the specific difference of the latter 

 can only be considered as doubtful. In the same manner the 

 continuance of the pure types under unchanged external cir- 

 cumstances, even if it has lasted for several thousand years, as 

 the Negro type in north-eastern Africa, is by itself alone in- 

 sufficient to establish them as specifically different. 



The last argued criterion of species and race has been used 

 by Blumenbach (and by Prichard after him) to found upon it a 

 long series of conclusions drawn from analogy. They chiefly 

 directed their attention to the question, whether the greatest 

 differences exhibited by human beings are only so great and no 

 greater than those presented by known races of animals, so 

 that we might be justified in considering them as differences of 

 race, or whether they are analogous to specific differences 

 among animals. Blumenbach, who may still be considered as 

 a chief authority, and a cautious observer, shows plainly l that 

 if the same laws determine the variability of types in animals 

 and man, the latter necessarily constitutes but one species, 

 since animals of the same species exhibit, as regards colour, 

 hair, size, cranial form, no greater differences, produced by 

 climate, food, etc., than are presented by human beings. 

 Essentially, Blumenbach has never been refuted, though he is 

 now ignored by those who find his arguments inconvenient ; for 



1 " De generis humani varietate nativa/' 3rd ed., p, 75, 1795. 



