LAMARCK’S THEORY OF DESCENT 281 
gression in organization of animals from the simplest 
to man, as also to the successive acquisition of different 
special organs, and consequently of as many faculties 
as new organs obtained, he remarks: 
“Then we can perceive how needs (desozs), at the 
outset reduced to nullity, and of which the number 
gradually increases, have produced the inclination 
(penchant) to actions fitted to satisfy it; how the ac- 
tions, becoming habitual and energetic, have caused 
the development of the organs which execute them; 
how the force which excites the organic movements 
may, in the simplest animals, be outside of them and 
yet animate them; how, then, this force has been 
transported and fixed in the animal itself; finally, 
how it then has become the source of sensibility, 
and in the end that of acts of intelligence. 
“T shall add that if this method had been followed, 
then sensation would not have been regarded as 
the general and immediate cause of organic move- 
ments, and it would not have been said that life is a 
series of movements which are executed in virtue of 
sensations received by different organs; or, in other 
words, that all the vital movements are the product 
of impressions received by the sensitive parts. * 
“ This cause seems, up to acertain point, established 
as regards the most perfect animals; but had it been 
so relatively to all living beings, they should all be 
endowed with the power of sensation. But it cannot 
be proved that this is the case with plants, and it 
cannot likewise be proved that it is so with all the 
animals known. 
“ But nature in creating her organisms has not be- 
gun by suddenly establishing a faculty so eminent 
*[Cabanis.] Rapp. du Phys. et du Moral de l’ Homme, pp. 38 4 
39, et 85. 
