54 
an enormous number of intermediate forms. Are such inter- 
mediate forms to be found ? Here we must, m the first place 
inquire how far, supposing the hypothesis true, it were to be 
expected that they should be found. The mode of production 
alleo-ed is a seizing hold by natural selection of profitable 
variations in individuals tending to the preservation of such 
to the exclusion of others. The same power that determines 
the greater predominance of the variant iWamiMB ilso the 
less predominance of the non-variant ; so that if the vanation 
be important, its preservation and confirmation carries with it, 
of necessity, the ultimate extinction both of the original, 
and also o/the successive steps by which the full extent of 
variation was attained. It is thus a necessary consequence 
of Darwinism that at no one time should a large number of 
intermediate forms be found co-existmg. Only m the case ^oi 
indifferent variations not much affected by natural selectio , 
or of other variations in particular stages of their progress 
was it to be expected that such forms would be found. The 
presence would be the exception their absence the ju a 
And iust so is it found to be in fact. Here and there are 
cases' (e.g. the brambles) where intermediate varieties are so 
numerous and so finely transitional as to ma 
impossible to determine which are species and which not . . I 
the majority of cases there is no such difficulty, but the specific 
differences are clearly marked. Again, precisely what the 
Darwinian hypothesis would have led us to expect. 
Yet another test. If all existing species are the descendants 
of other and different species/it is natural to expect to fi nd rn 
them various marks of this descent over and above those 
common characteristics of classes, orders, and genera before 
alluded to ; these marks varying m character according to t 
remoteness of the ancestor whom they concern. Thus it .is 
well known that in artificial breeds there is an occasional 
tendency to revert to the peculiarities of the original stock, 
and this especially when several distinct breeds are inter- 
crossed, and the variations of each thus neutralized by 
intermixture. The instance of the pigeons given by Mr. 
Darwin* will occur to every one who has read his book, ifie 
like reversion might naturally, then be expected to take 
place among species in nature. And the facts accumulated 
bv Mr. Darwin touching the occasional appearance ot stripes 
and bars on various species of the horse genus, and especia y 
on hybrids between any two of them,+ show unmistakeably 
that the same kind of phenomena does, m met, occur here also. 
* Pp. 26-7. 
f Pp. 191-5. 
