FULLER QUOTATIONS FROM < ZOONOMIA." 227 



and do not therefore marry, are armed with spurs for 

 the purpose of fighting for the exclusive possession of 

 the females, as cocks and quails. It is certain that 

 these weapons are not provided for their defence against 

 other adversaries, because the females of these species 

 are without this armour. The final cause of this 

 contest among the males seems to be that the strongest 

 and most active animal should propagate the species, 

 which should thence lecome improved" * 



Dr. Darwin would have been on stronger ground if 

 he had said that the effect of the contest among the 

 males was that the fittest should survive, and hence 

 transmit any fit modifications which had occurred to 

 them as vitally true, rather than that the desire to 

 attain this end had caused the contest ; but either way 

 the sentence just given is sufficient to show that he was 

 not blind to the fact that the fittest commonly survive, 

 and to the consequences of this fact. The use, however, 

 of the word " thence," as well as of the expression 

 " final cause," is loose, as Dr. Darwin would no doubt 

 readily have admitted. Improvement in the species is 

 due quite as much, by Dr. Darwin's own showing, to the 

 causes which have led to such and such an animal's 

 making itself the fittest, as to the fact that if fittest it 

 will be more likely to survive and transmit its improve- 

 ment. There have been two factors in modification ; 

 the one provides variations, the other accumulates 

 them ; neither can claim exclusive right to the word 

 " thence," as though the modification was due to it and 

 to it only. Dr. Darwin's use of the word " thence " 

 * Zoonomia,' vol. i. p. 507. 



Q 2 



