124 THE DARWINIAN HYPOTHESIS 



acquaintance 'svilh the lower forms of life than any man of 

 his day, Cuvicr not cxccptcd, and was a good botanist to 

 boot, occupies a prominent place. 



Two facts appear to have strongly affected the course 

 of thought of this remarkable man the one, that finer 

 or stronger links of affinity connect all living beings with 

 one another, and that thus the highest creature grades by 

 multitudinous steps into the lowest ; the other, that an 

 organ may be developed in particular directions by exerting 

 itself in particular ways, and that modifications once 

 induced may be transmitted and become hereditary. 

 Tutting these facts together, Lamarck endeavoured to 

 account for the first by the operation of the second. Place 

 an animal in new circumstances, says he, and its needs 

 will be altered ; the new needs will create new desires, and 

 the attempt to gratify such desires will result in an appro- 

 pirate modification of the organs exerted. Make a man a 

 blacksmith, and his brachial muscles will develope in 

 accordance with the demands made upon them, and in 

 like manner, says Lamarck, " the efforts of some short- 

 necked bird to catch fish without wetting himself have, 

 with time and perseverance, given rise to all our herons 

 and long-necked waders." 



The Lamarckian hypothesis has long since been justly 

 condemned, and it is the established practice for every 

 tyro to raise his heel against the carcass of the dead lion. 

 But it is rarely either wise or instructive to treat even the 

 errors of a really great man with mere ridicule, and in 

 the present case the logical form of the doctrine stands 

 on a very different footing from its substance. 



If species have really arisen by the operation of natural 

 conditions, we ought to be able to find those conditions 

 now at work ; we ought to be able to discover in nature 

 some power adequate to modify any given kind of animal 

 or plant in such a manner as to give rise to another kind, 

 which would be admitted by naturalists as a distinct species. 

 Lamarck imagined that he had discovered this vera causa 

 in the admitted facts that some organs may be modified 

 by exercise ; and that modifications, once produced, are 

 capable of hrmliUiry transmission. It docs not seem 

 to have occurred to him to inquire whether there is any 

 n ;ison to believe that there are any limits to the amount 

 of modification producible, or to ask how long an animal 

 is likely to endeavour to gratify an impossible desire. The 



