The Making of Species 
The former are the larger body, and pin their 
faith absolutely to natural selection. They deny 
the inheritance of acquired characters, and preach 
the all-sufficiency of natural selection to explain 
the varied phenomena of nature. The Neo- 
Lamarckians do not admit the omnipotency of 
natural selection. Some of them allow it no 
virtue. Others regard it as a force which keeps 
variation within fixed limits, which says to each 
organism, “thus far shalt thou vary and no 
farther.” This school lays great stress on the 
inheritance of acquired characters, especially 
on the inheritance of the effects of use and 
disuse. 
The above statement of the recent develop- 
ments of Darwinism is incomplete, for it fails to 
include those who occupy a middle position. If 
it be possible to classify a large number of men 
of which scarcely any two hold identical views, 
it is into three, rather than two, classes that they 
must be divided. 
Speaking broadly, evolutionists of to-day may 
be said to represent three distinct lines of thought. 
For the sake of classification we may speak of 
them as falling into three schools, which we may 
term the Neo-Lamarckian, the Wallaceian, and 
the Neo-Darwinian, according as their views in- 
cline towards those held by Lamarck, Wallace, 
or Darwin. 
As adherents of the Neo-Lamarckian school, 
14 
