212 FROM THE GREEKS TO DARWIN 



passes on to illustrations of the causes and prin- 

 ciples of trans formism. 



Darwin seems to realize that he will be charged 

 with irreverence in thus substituting the idea of 

 Evolution for that of Special Creation; he meets 

 this by establishing his evolution hypothesis upon 

 a basis of natural causation or secondary causes. 



As pointed out above, his fundamental theory 

 in the origin of new adaptations is what has since 

 been called 'archsesthetism' by Cope.^ Accord- 

 ing to this, growth is stimulated by irritability 

 and sensibility, or — in Darwin's language^ — in 

 the passage upward from the original filament : 



The most essential parts of the system . . . are 

 first formed by the irritations above mentioned [hun- 

 ger, thirst, etc.], and by the pleasurable sensations 

 attending those irritations, and by the exertions in 

 consequence of painful sensations, similar to those of 

 hunger and suffocation. ... In confirmation of 

 these ideas it may be observed, that all the parts of 

 the body endeavour to grow, or to make additional 

 parts to themselves throughout our lives. 



I have carefully searched for these passages, 

 and find a most striking confirmation of Charles 

 Darwin's well-known sentence: "It is curious 

 how largely my grandfather, Doctor Erasmus 



1 E. D. Cope: Origin of the Fittest, 1887, pp. 405-21. 

 ^ Zoonomia, vol. 1, xxxix. 



