Exfoliation 



his descendants, and the transformation is thus 

 carried on and completed later. For everywhere 

 among the animals there is desire, of some kind 

 or another, obviously acting ; and if in man, by 

 our own experience, desire is the precursor and 

 first expression of growth, is there any reason 

 why it should not also be so among animals ? 

 Lamarck gives the instance — among others — 

 of a gasteropod ; how the need or desire of touch- 

 ing bodies in front of it as it crawled along would 

 result in the formation of tentacles. The gaste- 

 ropod, he says, would keep making efforts to feel 

 with the front of its head, and the determination 

 of consciousness that way would be accompanied 

 by a supply of nervous and other fluids, which would 

 nourish the part and cause growth there — the 

 form of the growth continuing in the same way 

 to be determined by need — till at last two or more 

 tentacles would appear. True, the inward deter- 

 minations of consciousness may not be so vivid 

 and varied in animals as they are in men ; but 

 they are persistent, and by the very cumulative 

 force of habit which is so strong in animals, must 

 at length penetrate down through function into 

 organisation and external form. Who shall say 

 that the lark, by the mere love of soaring and 

 singing in the face of the sun, has not altered the 

 shape of its wings, or that the forms of the shark 

 or of the gazelle are not the long-stored results 

 of character leaning always in certain directions, 

 as much as the forms of the miser or the libertine 



are among men } 



189 



