10 
DARWINISM 
CHAP. 
Species should he carefully considered. It is as follows : 
“ Although much remains obscure, and will long remain 
obscure, I can entertain no doubt, after the most deliberate 
and dispassionate judgment of which I am capable, that the 
view which most naturalists until recently entertained and 
which I formerly entertained—namely, that each species has 
been independently created — is erroneous. I am fully con¬ 
vinced that species are not immutable; but that those 
belonging to what are called the same genera are lineal 
descendants of some other and generally extinct species, in 
the same manner as the acknowledged varieties of any one 
species are the descendants of that sjjecies. Furthermore, 1 
am convinced that Natural Selection has been the most im¬ 
portant, but not the exclusive, means of modification.” 
It should be especially noted that all which is here claimed 
is now almost universally admitted, while the criticisms of 
Darwin’s works refer almost exclusively to those numerous 
questions which, as he himself says, “ will long remain 
obscure.” 
The Darwinian Theory. 
As it will be necessary, in the following chapters, to set 
forth a considerable body of facts in almost every department 
of natural history, in order to establish the fundamental 
propositions on which the theory of natural selection rests, 
I propose to give a preliminary statement of what the theory 
really is, in order that the reader may better appreciate the 
necessity for discussing so many details, and may thus feel a 
more enlightened interest in them. Many of the facts to be 
adduced are so novel and so curious that they are sure to be 
appreciated by every one who takes an interest in nature, but 
unless the need of them is clearly seen it maybe thought that 
time is being wasted on mere curious details and strange facts 
which have little bearing on the question at issue. 
The theory of natural selection rests on two main classes 
of facts which apply to all organised beings without exception, 
and which thus take rank as fundamental principles or laws. 
The first is, the power of rapid multiplication in a geometrical 
progression ; the second, that the offspring always vary slightly 
from the parents, though generally very closely resembling 
