1894.] Neo-Lamarckism and Neo-Darwinism. 661 
NEO-LAMARCKISM AND NEO-DARWINISM. 
By L. H; BAILEY: 
It is difficult to accept the hypothesis of organic evolution 
in the abstract. In the first place, there must be some reason 
for the operation of a law of transformation or development ; 
and this is found in the ever-changing physical or external 
conditions of existente, which are more or less opposed to 
established organisms. And it may also be said that the very 
fact of the increase of organisms through multiplication must 
impose new conditions of competition upon every succeeding 
generation. Again, it is necessary to conceive of some means 
or machinery by which the process of evolution is carried 
forward. It was long known that all species vary, that is, that 
no two individuals in nature are exactly alike; yet there was 
lacking any hypothesis to show either why these varieties ap- 
pear or how it is that some become permanent and some do 
not. The first scientific explanation of the process of evolu- 
tion was that made in 1809 by the now famous Lamarck. He 
saw two factors which, he thought, were concerned in the trans- 
formation of species—the habitat and the habit. The habitat 
is the condition in which the organism lives, the environment. 
This environment, subject to change with every new indi- 
vidual, calls for new habits to adapt the organism to the new 
needs—inducing greater exercise of some powers or organs 
and less exercise of others. "This greater or less use gradually 
strengthens or enfeebles the organ concerned, and the modifi- 
cations thus acquired are preserved “through heredity to the 
new individuals that are produced by them, provided the 
chauges are common to the two sexes, or to those that have 
produced these new individuals." "There are three things to 
be considered in this hypothesis: 1. Changes in environment 
or the conditions of life react upon organisms in the direction - 
of their needs or functions. 2. Organs or powers thus affected 
are modified to satisfy the new demands. 3. The modifications 
! Extract from an address before the Philosophical Club of Cornell University. Ty 
