PHENOMENA OF CONVERGENCE. 17 



few remarks upon the origin of the idea of con- 

 vergence will, therefore, not be out of place. 



As soon as the idea has been grasped that 

 mechanism governs an organism with the same 

 regularity as it does an inorganic body, the ques- 

 tion must naturally arise how far the living sub- 

 stratum can be influenced by outward circum- 

 stances, and how far the same results independent 

 of one another may be attained under the same 

 and similar conditions. The genius of Diderot 

 comprehended the problem in its widest applic- 

 ability. In a conversation with d'Alembert in 1769, 

 he makes the latter start the supposition that 

 after the destruction of all life by the extinction of 

 the sun, a repetition of the development of the 

 plants and animals that formerly existed would 

 recommence with the rekindling of the heavenly 

 body which diffuses force and life. For, he adds, 

 nothing else is conceivable but that the causes, 

 once again set in motion, should produce the same 

 effects as they had already done. According to the 

 Linnaean and Cuvier's interpretation of species, 

 this idea could scarcely expect to find acceptance, 

 and it is self-evident that any agreement was made 

 to rest upon the same origin of the individuals of 

 the species, and further upon the same fundamental 



