which characterises all the members of a species, must 
lead to much confusion of thought. If prolificness can 
secure the survival of a species, in spite of the absence of 
all adaptation of structure to new environment, the neces 
sity for Natural Selection is excluded. But prolificness 
is an essential element in the action of Natural Selection. 
Thus the very condition which is necessary for the intro 
duction of Natural Selection dispenses with the necessity 
for its interposition. 
We now proceed to consider Mr. Spencer’s proof that 
Natural Selection has co-operated in the evolution of the 
earliest forms of life. At the outset of this enquiry, it will 
be well to bear in mind that we are moving in a sphere of 
conjecture more or less. Mr. Spencer thus concludes his 
Essay:— 
“ Of course, this sketch of the relations among the factors must be 
taken as in large measure a speculation. We are now too far removed 
from the beginnings of life to obtain data for anything more than 
tentative conclusions respecting its earliest stages, especially in the 
absence of any clue to the mode in which multiplication—first 
agamogenetic and then gamogenetic—was initiated.”—(p. 74.) 
In the second place, we must remember that the simplest 
forms of life may not represent in all cases the actual 
ancestry of the higher organisms. They have existed 
almost from the beginning of the appearance of life upon 
the earth, and they may have undergone considerable 
modifications. Still, it would be a mistake to allow too 
much force to this difficulty. We have instances of the 
simplest forms of living matter still existing either in a 
permanent or a transitional form ; and, on the principle of 
Organic Evolution, we are bound to believe that develop 
ment must have taken place in some way or other from 
the simplest form to the less simple, from the less com 
plex to the more complex.