LAMARCK. fil57 



In his earlier work this was first expressed by 

 Lamarck as follows : — 



" All that Nature has caused individuals to acquire or lose by 

 the influences of environment to which they have been long 

 exposed, and consequently by the influence of the predominant 

 employment of a certain organ, or by that of the continued lack 

 of use of the same part, — all this Nature conserves by generation 

 to the new individuals which arise, provided that these acquired 

 variations (changements) are common to both sexes, or to those 

 which have produced these new individuals." 



This law is now known as ' the inheritance of 

 acquired characters,' or better, to reyive Lamarck's 

 original idea expressed in the word changements., 

 we should call it the theory of inheritance of 

 acquired changes or variations. 



This theory ' of Lamarck is seen to be substan- 

 tially similar to that of Erasmus Darwin, and to 

 depart widely from that of Buffon, for Lamarck 

 does not follow Buffon in supposing that environ- 

 ment directly produces changes in animals, either 

 in their form or oro-^ . 'ation. In a single sentence 



' Premure loi. — iropres forces, tend continuellement i. 



accrottre le volume de lossede, et \ etendre les dimensions 



de ses parties, jusqu'i ur. "-ne elle-meme. 



Deuxieme loi. — La pi vel organe dans un corps animal 



resulte d'un nouveau besoin inue de se faire sentir, et d'un 



nouveau mouvement que ce L entretient. 



Troisieme loi. — Le develo) °s et leur force d'action sont 

 constamment en raison de I'empl 



Quatrieme loi. — Tout ce qui a u change dans I'organisa- 



tion des individus, pendant le cours serve par la generation 



et transmis aux nouveaux individus qu- -.eux qui ont eprouve 

 ces changements. 



