236 LAMARCK, AIS LIFE AND WORK 
and modern form the essential principles of evolution. 
Lamarck insists that time without limit and favorable 
conditions are the two principal means or factors in 
the production of plants and animals. Under the 
head of favorable conditions he enumerates variations 
in climate, temperature, the action of the environ- 
ment, the diversity of local causes, change of habits, 
movement, action, variation in means of living, of 
preservation of life, of means of defence, and varying 
modes of reproduction. As the result of the action 
of these different factors, the faculties of animals, 
developed and strengthened by use, become diversi- 
fied by the new habits, so that by slow degrees the 
new structures and organs thus arising become pre- 
served and transmitted by heredity. 
In this address it should be noticed that nothing is 
said of willing and of internal feeling, which have been 
so much misunderstood and ridiculed, or of the direct 
or indirect action of the environment. He does 
speak of the bird as wishing to strike the water, but 
this, liberally interpreted, is as much a physiological 
impulse as a mental desire. No reference also is 
made to geographical isolation, a factor which he 
afterwards briefly mentioned. 
Although Lamarck does not mention the princirle 
of selection, he refers in the following way to compe- 
tition, or at least to the checks on the too rapid mul- 
tiplication of the lower invertebrates: 
“So were it not for the immense consumption as 
food which is made in nature of animals which com- 
pose the lower orders of the animal kingdom, these 
animals would soon overpower and perhaps destroy, 
