THE ORIGIN OF SPECIES 75 
even in the least degree, infertile with | 
he_f Mr. Darwin is is perfectly aware of this 
ak point, and brings forward a multitude of 
ng enious and important arguments to diminish 
e force of the objection. We admit the value of 
|these arguments to their fullest extent; nay, we 
will go so far as to express our belief that experi- 
)ments, conducted by askilful physiologist, would very 
srobably obtain the desired production of mutually 
more or less infertile breeds from a common stock, 
| im a comparatively few years ; but still, as the case 
} stands at present, this “little rift_within the lute”. 
‘is not_to be disguised_nor overlooked. 
In the remainder of Mr. Darwin’s argument our 
} own private ingenuity has not hitherto enabled us 
| to pick holes of any great importance ; and judging 
‘by what we hear and read, other adventurers in 
‘the same field do not seem to have been much 
more fortunate. It has been urged, for instance, 
‘that in his chapters on the struggle for existence 
and on natural selection, Mr. Darwin does not so 
‘much prove that natural selection does occur, as. X 
that it must occur; but, in fact, no other sort of 
demonstration is attainable. A-race does not 
attract our attention in Nature until it has, im all 
eility, existed for a considerable time, and 
then it is too late to inquire into the conditions. of 
- its origin. Again, it is said that there is no real 
analogy between the selection which takes. place 
under domestication, by human influence, and any 
om ey pene 
