4-06 PALAEONTOLOGY 



that time of the year when food was scarcest ; they would 

 also rear more young, which would tend to inherit these 

 slight peculiarities. The less fleet ones would be rigidly 

 destroyed. I can see no more reason to doubt that these 

 causes in a thousand generations would produce a marked 

 effect, and adapt the form of the fox or dog to the catching of 

 hares instead of rabbits, than that greyhounds can be improved 

 by selection and careful breeding.* 



Observation of animals in a state of nature, however, is 

 still required to show their degree of plasticity, or the extent 

 to which varieties do arise ; whereby grounds may be had for 

 judging of the probability of the elastic ligaments and joint- 

 structures of a feline foot, for example, being superinduced 

 upon the more simple structure of the toe with the non- 

 retractile claw, according to the principle of a succession of 

 varieties in time. 



Farther discoveries of fossil remains are also needed to 

 make known the antetypes, in which varieties, analogous to 

 the observed ones in existing species, might have occurred, 

 seriatim, so as to give rise ultimately to such extreme forms 

 as the Giraffe. 



This application of palaeontology has always been felt by 

 myself to be so important that I have never omitted a proper 

 opportunity for impressing the results of observations showing 

 the "more generalized structures" of extinct, as compared 

 with the "more specialized forms" of recent animals. 



But observation of the effects of any of the above hypo- 

 thetical transmuting influences in changing any known species 

 into another has not yet been recorded. And past expe- 

 rience of the chance aims of human fancy, unchecked and 

 unguided by observed facts, shows how widely they have ever 

 glanced away from the gold centre of truth. 



* Proceedings of the Linnaesn Society, August 1858, p. 49. The principle 

 is more fully illustrated in the work "On the Origin of Species," 8vo, 1859. 



