THE ORIGIN OF SPECIES 169 



But De Maillet was before his age, and as could hardly fail 

 to happen to one who speculated on a zoological and botani- 

 cal question before Linnaeus, and on a physiological problem 

 before Haller, he fell into great errors here and there ; and 

 hence, perhaps, the general neglect of his work. Robinet's 

 speculations are rather behind, than in advance of, those of 

 De Maillet ; and though Linnaeus may have played with the 

 hypothesis of transmutation, it obtained no serious support 

 until Lamarck adopted it, and advocated it with great 

 ability in his Philosophie Zoologique. 



Impelled towards the hypothesis of the transmutation of 

 species, partly by his general cosmological and geological 

 views ; partly by the conception of a graduated, though 

 irregularly branching, scale of being, which had arisen out 

 of his profound study of plants and of the lower forms of 

 animal life, Lamarck, whose general line of thought often 

 closely resembles that of De Maillet, made a great advance 

 upon the crude and merely speculative manner in which that 

 writer deals with the question of the origin of living beings, 

 by endeavouring to find physical causes competent to effect 

 that change of one species into another, which De Maillet 

 had only supposed to occur. And Lamarck conceived that 

 he had found in nature such causes, amply sufficient for the 

 purpose in view. It is a physiological fact, he says, that 

 organs are increased in size by action, atrophied by inaction ; 

 it is another physiological fact that modifications produced 

 are transmissible to offspring. Change the actions of an 

 animal, therefore, and you will change its structure, by 

 increasing the development of the parts newly brought into 

 use and by the diminution of those less used ; but by alter- 

 ing the circumstances which surround it you will alter its 

 actions, and hence, in the long run, change of circumstance 

 must produce change of organization. All the species of 

 animals, therefore, are, in Lamarck's view, the result of the 

 indirect action of changes of circumstance upon those 

 primitive germs which he considered to have originally 

 arisen, by spontaneous generation, within the waters of the 

 globe. It is curious, however, that Lamarck should insist 

 so strongly * as he has done, that circumstances never in 

 any degree directly modify the form or the organization of 

 animals but only operate by changing then- wants and con- 

 sequently their actions ; for he thereby brings upon himself 

 the obvious question> how, then, do plants, which cannot be 

 * See Phil. Zoologique, vol. i. p. 222, et seq. 



