28 Evolution by Expansion. [January, 
The theory of the origin of species by gradual develop- 
ment, or, more properly, by descent, is often regarded as 
identical with, dependent on, or so closely connected with 
that of natural selection, as to stand or fall with it. Darwin 
himself, in many instances, appears to consider development 
by descent or evolution as almost synonymous with develop- 
ment by natural selection. The theory of natural selection 
is, however, merely a method of accounting for or explaining 
the gradual development of species ; and it may be sound 
or not, without affedting the validity of the theory of 
descent. 
It is my objedt in this paper to compare this theory of 
natural selection with that which supposes the existence of 
an innate force,' * and to show that the latter affords the more 
satisfadtory explanation of the principal fadts of natural 
history, physiology, palaeontology, &c. 
For this purpose X will assume the truth of the theory of 
the origin of species by gradual development. It has been 
so ably defended by Darwin, in his “ Origin of Species,” as 
to leave no new argument to be urged in its favour. The 
greatest difficulty which it presents, and perhaps the only 
one of any importance, is the absence of intermediate links 
or gradations between existing species : this he accounts for 
on the theory of the survival of the fittest only in the 
struggle for life, and by the imperfedtion of the geological 
records. 
The inadequacy of the theory of natural seledtion to 
explain all the phenomena of natural history in a thoroughly 
satisfadtory manner has undoubtedly caused many eminent 
naturalists to retain their belief in the old theory of 
creation. 
Notwithstanding all the ingenuity of Darwin’s argu- 
ments, and the vast amount of learning and scientific re- 
search he has brought to bear on the subjedt in support of 
his theory, a thoughtful reader — though much interested, 
and perhaps somewhat perplexed — must close his work on 
the “ Origin of Species ” with a feeling of dissatisfadtion ; 
he cannot realise that such haphazard means as natural 
seledtion and the survival of the fittest can alone have 
wrought such marvels as are exhibited throughout creation ; 
nor, on the pritnd facie view of the case, that they alone 
* The term “ Force,” it must be clearly understood, is used in this paper, 
not in the sense of “ Germ Force ” or “ Will Force,” but to express merely a 
faculty of development; and that the word “growth” is used, not in the 
restricted sense of mere “ enlargement,” but in the more extended one of 
“ progress” or “ improvement.” 
