REY. JOHN GERARD, F.L.S., ON SPECIES AND THEIR ORIGIN. 133 
elegans and caniceps. On the other hand, although the 
common primrose (Primula vulyaris) and the cowslip (P. veris) 
are acknowledyed to be but varieties of one species, it has 
proved so difficult as to be well-nigh impossible to obtain 
crosses between them.* 
So, again, there are genera which Mr. Darwin styles “ protean 
or polymorphic,” in which the species present an inordinate 
amount of variation, with the result, as he adds, that hardly 
two naturalists agree whether to rank them as species or as 
varieties, examples being, amongst plants, the genera Rubus, 
Rosa, and Hieracium ; amongst animals several kinds of insects 
and Brachiopod Shells.| Some authorities in consequence 
multiply the number of species prodigiously, whilst others 
reduce this toa minimum. It is not an unusual experience to 
find that as a man grows older he becomes less inclined to 
favour the larger figures. 
The whole question appears to be, Are there or are there 
not “natural species,” species which have for their basis some- 
thing in nature which impresses upon the individuals of which 
they are constituted the common characteristics according to 
which we classify them? Among the higher and more 
developed classes, both of the vegetable and animal kingdoms, 
there seem certainly to be groups thus stamped with characters 
marking them as connected by a bond which man does not 
make but recognise; and, if such groups there are, it seems 
impossible to avoid the conclusion that there are in nature 
really existent species. 
If so, we are of necessity driven back on the enguiry, what 
cause can possibly be supposed capable of producing such 
uniformity ? And it is not easy to understand how any answer 
to the question can be found which is even plausible, except 
that the orderly disposition of nature which mind alone can 
discern, mind alone can have instituted. Very specially, we 
may add, should this be the lesson which we learn’ from 
science, for if there be one conviction more than another 
which is borne in upon us by every fresh investigation in all 
her fields it is that all things have been ordered “in measure, 
and number, and weight.” So it is that, in every nook and 
cranny of her domain, we are able to discover laws which 
human wit is only now beginning after all these ages dimly 
and partially to descry, but which have been in operation from 
* Darwiniana, p. 4. 
t+ Origin, p. 35. 
