Survival of the Fittest. 441 
act on and modify organic beings at any age, by the accu- 
mulation of variations useful at that age, and by their 
inheritance at a corresponding age. Thus, if it be profitable 
to a plant to have its seeds more and more widely dissemi- 
nated by the wind, there can be no greater difficulty in 
conceiving this to be effected through Natural Selection than 
in conceiving the increasing and improving of the down in 
the pods on his cotton-trees by a wise selection upon the 
part of a cotton-planter. Natural Selection may modify and 
adapt the larva of an insect to a score of contingencies, 
wholly different from those which affect the mature insect, 
and these modifications through Correlation may work 
changes in the structure of the adult. On the other hand, 
modifications of the adult may affect the structure of the 
larva, but in all such cases Natural Selection will insure that 
these changes shall not be injurious, for, if they were so, 
the extinction of the species would be the inevitable result. 
Thousands of instances might be given to show the influ- 
ence which Natural Selection, or Sexual Selection, which is 
only a less vigorous phase of the former, has had all through 
the ages in the adaptation of life to the places in nature 
which it was intended to occupy in pursuance of the 
plan formulated by the Great Originator and Designer of 
the Universe. 
Despite the imperfection of the geological record, which 
has been urged as a serious objection to the theory of descent 
with modification, sensible, intelligent, educated men no lon- 
ger doubt that species have all changed, and that they have 
changed in the way required, for they have changed slowly 
and in a graduated manner. This is clearly seen in the fossil 
remains from consecutive formations being invariably much 
more closely allied to each other than are those from widely- 
separated formations. It is true geological research does 
not yield those infinitely fine gradations between past and 
present species which the theory of Natural Selection requires, 
but when it is remembered that only a small portion of the 
