LAMARCK'S THEORY OF DESCENT 



305 



" Assuredly, if the habits and nature of each animal 

 can never vary, the proverb is false, has no founda- 

 tion, and does not apply to the instances which led 

 to its being spoken. 



" If we should seriously consider all that I have 

 just stated, it might be thought that I had good rea- 

 son when in my work entitled Recherches sur les Corps 

 vivans (p. 50) I established the following proposition : 



" ' It is not the organs — that is to say, the nature 

 and form of the parts of the body of an animal— which 

 have given rise to its habits and its special faculties ; 

 but it is, on the contrary, its habits, its manner of 

 life, and the circumstances in which are placed the 

 individuals from which it originates, which have, with 

 time, brought about the form of its body, the num- 

 ber and condition of its organs, finally, the faculties 

 ■wrhich it enjoys.' 



"If we weigh this proposition, and if we recall all 

 the observations which nature and the state of things 

 continually lead us to do, then its importance and 

 its solidity will become more evident. 



" Time and favorable circumstances are, as I have 

 already said, the two principal means which nature 

 employs to give existence to all her productions : we 

 know that time for her has no limits, and that conse- 

 quently it is ever at her disposal. 



" As to the circumstances of which she has need, 

 and which she uses still daily to cause variations in 

 all that she continues to produce, we can say that 

 they are, in some degree, for her inexhaustible. 



" The principal circumstances arise from the in- 

 fluence of climate ; from those of different tempera- 

 tures of the atmosphere, and from all the environing 

 media ; from that of the diversity of different locali- 

 ties and their situation ; from that of habits, the 

 ordinary movements, the most frequent actions ; 

 finally, from that of means of preservation, of mode 

 of living, of defence, of reproduction, etc. 



