LAMARCKA SOLTALORY: 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. 
“Tf 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: 
“<«Tt 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 
which it enjoys.’ 
“Tf 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. 
