366 OUTLINES OF EVOLUTIONARY BIOLOGY 



rate strong leanings towards the theory of organic evolution, 

 although, unfortunately, he seems to have found it very difficult 

 to give a frank expression to his views. The following trans- 

 lated extracts will serve to illustrate his position. 



Speaking of the arbitrary character of our systems of classifi- 

 cation he observes : 



" But Nature proceeds by unrecognized gradations and con- 

 sequently she cannot lend herself completely to these divisions, 

 since she passes from one species to another species, and often 

 from one genus to another genus, by imperceptible shades : so 

 that we find a great number of intermediate species and objects 

 which we do not know where to place, and which necessarily 

 upset the plan of the general system." 1 



Buffon certainly appears in this passage as no believer in the 

 immutability of species, and amongst the causes which bring 

 about their modification he attributes great importance to the' 

 action of climate: 



"If we again consider each species in different climates, we 

 shall find obvious varieties both as regards size and form ; all 

 are influenced more or less strongly by the climate. These 

 changes only take place slowly and imperceptibly ; the great 

 workman of Nature is Time : he walks always with even strides, 

 uniform and regular, he does nothing by leaps ; but by degrees, 

 by gradations, by succession, he does everything ; and these 

 changes, at first imperceptible, little by little become evident, 

 and express themselves at length in results about which we 

 cannot be mistaken." 2 



In dealing with the animals of the old and the new worlds, and 

 after speaking of the extinction of the mammoth, he says : 



" This species was certainly the foremost, the largest and the 

 strongest of all the quadrupeds : inasmuch as it has disappeared, 

 how many other smaller ones, weaker and less remarkable, have 

 had to succumb also, without having left us either witness or 

 evidence of their past existence ? How many other species, having 

 become modified in their nature, that is to say, perfected or 

 degraded by the great vicissitudes of land and sea, by the neglect 

 or the culture of Nature, by the long influence of a climate 

 become contrary or favourable, are no longer the same that they 

 formerly were ? And, moreover, the quadrupeds are, next to 

 man, the beings whose nature is the most fixed and whose form 

 is the most constant : that of the birds and of the fishes varies 



1 Buffon, " Histoire Naturelle," Tom. I, p. 13. 

 * Op. eit., Tom. VI, pp. 50, 60. 



