196 Luck, or Cunning ? 
accumulation of modification in various directions, and 
hence wide eventual difference between species descended 
from common progenitors—no evolutionist since 1750 has 
doubted this—but whether a general principle underlies the 
modifications from among which the quasi-selection is 
made, or whether they are destitute of such principle and 
referable, as far as we are concerned, to chance only. 
Waiving this again, we note that the theories of inde- 
pendent creation and of natural selection are contrasted, 
as though they were the only two alternatives; knowing 
the two alternatives to be independent creation and descent 
with modification, we naturally took natural selection to 
mean descent with modification. 
Again :— 
“ On the theory of natural selection we can satisfactorily 
answer these questions ”’ (p. 437). 
“ Satisfactorily ’ now stands “ to a certain extent.” 
Again :— 
“ On my view these terms may be used literally ” (pp. 438, 
439). 
“On my view” became “ according to the views here 
maintained such language may be,” &c., in 1869. 
Again :— 
“‘T believe all these facts can be explained as follows, 
on the view of descent with modification” (p. 443). 
This sentence now ends at “‘ follows.” 
Again :— 
“ Let us take a genus of birds, descended, on my theory, 
from some one parent sfecies, and of which the several new 
species have become modified through natural selection in 
accordance with their divers habits” (p. 446). 
The words ‘‘ on my theory ” were cut out in 1869, and 
the passage now stands, “ Let us take a group of birds, 
descended from some ancient form and modified through 
natural selection for different habits,” 
