564 THE POPULAR SCIENCE MONTHLY 



tributes an identical origin. But it is possible that he has here merely 

 lapsed (as he apparently does occasionally elsewhere) into the terminol- 

 ogy in which he was brought up, and is using the word species in the 

 Linnasan sense rather than in his own. 



More significant, perhaps, than this possibly inadvertent incon- 

 sistency is the fact that, in his fourteenth volume 34 (1766), Buffon 

 seems to raise explicitly the question — though only as a question — 

 whether, after all, descent with modification may not extend to species 

 as well as varieties. 



After surveying the varieties which indicate to us the alterations that each 

 species has undergone, there arises a larger and more important question, namely, 

 how far species themselves can change — how far there has been a more ancient 

 modification, immemorial from all antiquity, which has taken place in every 

 family, or, if the term be preferred, in all the genera in which species that 

 closely resemble one another are to be found. There are only a few isolated 

 species which are like man in forming at once a species and a whole genus. Such 

 are the elephant, rhinoceros, hippopotamus and giraffe, which constitute genera, 

 or simple species, and descend in a single line, with no collateral branches. But 

 all other races have the appearance of forming families, in which we may 

 perceive a common source or stock from which the different branches seem to 

 have sprung. 35 



Even here one can not be wholly sure that Buffon is not referring 

 to Linnasan species, and using the word genera to indicate what he usu- 

 ally means by species in the strict sense. Assuming, however, that he 

 is speaking of " true " species, it must be observed that while he raises 

 the question of their mutability, he does not answer it finally in the 

 affirmative. For the passage is shortly followed by that cited earlier in 

 this paper, in which Buffon, though he derives many species tradition- 

 ally regarded as distinct from a common stock, yet finds even in " the 

 first ages of nature " thirty-eight irreducible diversities of specific type 

 among quadrupeds. 



There is, however, one peculiarly interesting essay in which Buffon 

 shows himself a little dubious even about that " most fixed point in 

 nature " upon which his usual doctrine of the reality and constancy of 

 species was based — namely, the fact of the sterility of hybrids. As I 

 have already mentioned, this seemed to him so central a point in nat- 

 ural history that he for many years assiduously collected data concern- 

 ing it, and caused experiments bearing thereon to be made and carefully 

 recorded at his own estate at Montbard. The results of these inquiries, 

 which he reports in the chapter " On Mules " (in the third supplemen- 

 tary volume, 1776), led him to the conclusion that hybrids are not 

 necessarily without hope of posterity. On the testimony of an affidavit 

 from a gentleman in San Domingo, Buffon declares that in hot climates 

 mules have been known to beget offspring of mares, and females of their 



34 Just a year earlier we have found Buffon using the most exaggerated 

 language possible about the changelessness of species. 



35 Vol. XIV., p. 335; italics mine. 



