BUFFO N AND THE PROBLEM OF SPECIES 557 



degeneration from another species is an impossibility for nature, the number of 

 probabilities against it is so enormous that even on philosophical grounds one 

 can scarcely have any doubt upon the point. 21 



However plausibly Buffon's incidental expressions of deference to 

 the testimony of revelation may be regarded as perfunctory and insin- 

 cere, it would be absurd to suppose that he was also ironical in these 

 legitimate and ostensibly scientific (however poor) arguments for the 

 fixity of species — arguments which are closely connected with that 

 conception of the nature of species which was perhaps his most influ- 

 ential personal contribution to the biological ideas of his time. We 

 must conclude, then, that, while he clearly envisaged the hypothesis of 

 evolution as early as 1753, and recognized that there was some probable 

 evidence in its favor, he then seriously believed that the preponderance 

 of probability was enormously against it. It is certain that contem- 

 porary readers must have understood this to be his position. 



The same doctrine — that true species, as determined by the sterility 

 of hybrids, are real natural entities and constant units amid the other- 

 wise infinitely variable phenomena of organic nature — is repeated and 

 emphasized many times in subsequent volumes of the " Histoire Nat- 

 urelle." Thus in volume five (1755) Buffon — trying to retain as much 

 of the principle of continuity as could be made consistent with his 

 present view — writes as follows : 



Although animal species are all separated from one another by an interval 

 which nature can not overstep, some of them seem to approximate one another 

 by so great a number of relations, that there remains between them only so 

 much of a gap as is necessary to establish the line of separation. 22 



In the same volume he insists upon the equal antiquity of all real 

 species, in the very passage in which he emphasizes the possibility of a 

 wide range of variation within the species: 



Though species were formed at the same time, yet the number of generations 

 since the creation has been much greater in the short-lived than in the long-lived 

 species; hence variations, alterations, and departures from the original type, 

 may be expected to have become far more perceptible in the case of animals 

 which are so much farther removed from their original stock. 21 



This is advanced as a partial explanation of the extreme diversity 

 of breeds in the canine species : the dog is a short-lived animal and has 

 therefore been capable of a relatively great degree of diversification. 



A little later (in Vol. VI., 24 1756) Buffon declares that "nature 



21 These, the most definite and decisive words on the subject to be found 

 anywhere in Buffon 's writings, have been strangely disregarded by most of those 

 who have discussed his attitude towards evolutionism. Samuel Butler can scarcely 

 be acquitted of suppressing the passage, fatal to his theory. For he quotes in 

 full the opening part of the passage, leaving off abruptly at the point where 

 Buffon begins to introduce his serious objections to the theory of descent. 

 Cf. "Evolution Old and New," p. 91. 



22 P. 59 (italics mine). 



23 P. 194. 



24 P. 55. 



