Vv. VARIETIES, ETC. 51 
the less adapted forms to die in the struggle for ground whereon 
to live. This is “ Natural Selection,” or selection by natural 
agencies. The better adaptation of the variation or variety to the 
external circumstances conserves it; the external circumstances 
select (figuratively) the variety or variations to be conserved. 
Accumulated variations change the species, —even the genus or 
order. 
From one point of view, and to a limited extent, this is such 
an obvious truth as to be simply a truism, which nobody would 
dispute, and nobody had taken the trouble to describe in detail or 
to endow with a special name. But it is an old and just saying 
“Nomina si nescis, perit cognitio rerum.” By giving a special 
name to the agency, describing its operation very clearly, illus- 
trating it in copious detail, showing its universality, and con- 
necting its phenomena together, Mr. Darwin has rendered vast 
service to the progress of natural science, and fairly made the 
previously rude recognition of this agency into a new and explana- 
tory theory of organic life. It is the characteristic of Mr. Darwin's 
reasoning, to heap fact upon fact, and to convince his readers by 
accumulations of evidences and illustrations,—always the most 
successful mode of addressing the miscellaneous public of readers. 
A more causal reasoner would have stated his principle or rule,— 
illustrated it by half a dozen examples,—left it then to make its 
own way,—and remained neglected or misunderstood for half a 
century. 
A man who only convinces himself, how warrantable soever 
that conviction may be, has done but little. Although guesses_ 
and suggestions about the gradual transition of past into present 
species, and even that varieties are less distinct species, and that 
species are more distinct varieties, were repeatedly made before 
Darwin wrote on the subject,—yet the scornful scepticism with 
which his first announcements were received by some of the most 
eminent naturalists of his day, abundantly testify that he had 
really carried onward previous crude ideas into something con- 
siderably different or more perfect, — virtually a novelty and a 
discovery, its truth being admitted. 
