290 LAY SERMONS, ADDRESSES, AND REVIEWS. xir. 



which cannot be said to have wants or actions, become 

 modified % To this he replies, that they are modified 

 by the changes in their nutritive processes, which are 

 effected by changing circumstances ; and it does not 

 seem to have occurred to him that such changes might 

 be as well supposed to take place among animals. 



When we have said that Lamarck felt that mere 

 speculation was not the way to arrive at the origin of 

 species, but that it was necessary, in order to the estab- 

 lishment of any sound theory on the subject, to discover 

 by observation or otherwise, some vera causa, competent 

 to give rise to them ; that he affirmed the true order of 

 classification to coincide with the order of their develop- 

 ment one from another ; that he insisted on the necessity 

 of allowing sufficient time, very strongly ; and that all 

 the varieties of instinct and reason were traced back by 

 him to the same cause as that which has given rise to 

 species, we have enumerated his chief contributions to 

 the advance of the question. On the other hand, from 

 his ignorance of any power in Nature competent to 

 modify the structure of animals, except the development 

 of parts, or atrophy of them, in consequence of a change 

 of needs, Lamarck was led to attach infinitely greater 

 weight than it deserves to this agency, and the absur- 

 dities into which he was led have met with deserved 

 condemnation. Of the struggle for existence, on which, 

 as, we shall see, Mr. Darwin lays such great stress, he had 

 no conception; indeed, he doubts whether there really 

 arc such things as extinct species, unless they be such 

 large animals as may have met their death at the hands 

 of man ; and so little does he dream of there being any 

 oilier destructive causes at work, that, in discussing 

 the possible existence of fossil shells, he asks, " Pourquoi 

 d'ailleurs seroient-ils pcrducs des que Thornine n'a pu 

 operer leur destruction?" (Phil. Zool., vol. i. p. 77.) 



