i 
88 CRITICISMS ON “THE ORIGIN OF SPECIES” 1 
the parents. . . The external conditions of life, as climate and — 
food, &c., seem to have induced some slight modifications, — 
Habit, in producing constitutional differences, and use, in 
strengthening, and disuse, in weakening and diminishing organs, ~ 
seem to have been more potent in their effects.” 
And finally, as if to prevent all possible miscon- 
. . . + 
ception, Mr. Darwin concludes his Chapter on 
Variation with these pregnant words :— 
‘* Whatever the cause may be of each slight difference in ia 
offspring from their parents—and a cause for each must exist—_ 
it is the steady accumulation, through natural selection of cual 
differences, when beneficial to the individual, that gives rise to 
all the more important modifications of structure, by which te 
innumerable beings on the face of the earth are enabled 
struggle with each other, and the best adapted to survive.” 3 
We have dwelt at length upon this subject, be- 
cause of its great ee importance, and becausdl 
we believe at Professor Kolliker’s criticisms on 
this head are based upon a misapprehension of Mr. | 
Darwin’s views—substantially they appear to us” 
to coincide with his own. The other objections 
which Professor Kolliker enumerates and discusses ; 
are the following : '— 
**1. No transitional forms between existing species are 
known; and known varieties, whether selected or spontaneous 
> 3 7 
never go so far as to establish new species.” 
To this Professor Kolliker appears to attach 
some weight. He makes the suggestion that the 
1 Space will not allow us to give Professor Kélliker’s argu- 
ments in detail ; our readers will find a full and accurate version 
of them inthe Reader for August 13th and 20th, 1864. 
Re 
