THE KINSHIP OF LIFE. 45 
of species in any group who entertains the old notion 
as to their distinct origin. There is not one who could 
hold this view and look an animal in the face! 
And for this change we have to thank Darwin. “It 
is easy to plough where the field is cleared,” and what 
he first of all saw clearly we can not fail to see now. 
The fact is that every student of species and of the 
facts of geographical distribution has reached, willingly 
or unwillingly, the conclusion that species are not im- 
mutable; that those differences by which he tried to 
discriminate the groups of organisms which he calls spe- 
cies were not differences originating in the act of crea- 
tion, but produced in some way by outside influences 
or by the organism’s reaction in adjustment-to these in- 
fluences. One might safely pledge himself to convert 
to some phase of the development theory any honest 
and intelligent man who would spend a month in a care- 
ful study of a large collection of specimens in any group 
in which the existing species are found over wide areas 
on the surface of the earth. The study of squirrels, 
eels, catfishes, pine trees, asters, butterflies, clams, snails, 
horses, or men—any of these will serve to accomplish 
this purpose. 
The general acceptance of the Darwinian theory by 
naturalists is not due exclusively to the Origin of Spe- 
cies or to any of the numerous- com- 
mentaries and expositions which have 
come from other hands. It arises from 
the results of the studies themselves. 
No authority has compelled it, for Darwin’s influence 
was not, like that of Cuvier or of Agassiz, the force of an 
overmastering personality. He was rather the voice of 
Nature. His word was the impersonal word of Nature 
herself. To see truthfully is to see with Darwin’s eyes. 
The idea of development gives the only clew by which 
The acceptance 
of the theory 
of descent, 
