382 OUTLINES OF EVOLUTIONARY BIOLOGY 



Lamarck summed up his views as to the factors which have 

 co-operated in organic evolution, at any rate so far as the animal 

 kingdom is concerned, in a later work, the " Histoire Naturelle 

 des Animaux sans Vertebres," published in 1815, in the form of 

 four " Laws," which may be taken as replacing the two " Laws " 

 of the " Philosophie Zoologique." They are as follows : 



" First Law : Life, by her own forces, tends continually to 

 increase the volume of every body which possesses it, and to 

 extend the dimensions of its parts, up to a limit which she 

 herself imposes." 1 



" Second Law : The production of a new organ in an animal 

 body results from a new requirement which continues to make 

 itself felt, and from a new movement which this requirement 

 begets and maintains." 2 



" Third Law : The development and efficiency of organs are 

 constantly in proportion to the use of these organs," 3 



" Fourth Law : All that has been acquired, traced out or 

 altered in the organization of individuals during the course of 

 their life, is preserved by generation, and transmitted to the 

 new individuals which originate from those which have 

 experienced these modifications." 4 



With regard to the position of man in the animal kingdom 

 Lamarck, unfortunately, does not seem to have been able, any 

 more than Buffon, to divest himself of the fetters of religious 

 orthodoxy. After pointing out at length the numerous ties by 

 which man, in his bodily organization, is united to the lower 

 animals, and especially his close relationship to the apes, he 

 saves himself, so to speak, in the following paragraph : 



" Such would be the reflections which one might make if man, 

 considered here as the pre-eminent race in question, were only 

 distinguished from the animals by the characters of his 

 organization, and if his origin were not different from theirs." 5 



1 " Histoire Naturelle des Animaux sans Vertebres," Tom. I, 1815, p. 182. 



2 Ibid., p. 185. 



3 Ibid., p. 189. 



4 Jbid., p. 199. 



5 " Philosophic Zoologique," Tom. I, p. 357. 



