CfrAP. XIV. 
CONCLUSION. 
485 
admitted, we can dimly foresee that there will be a con¬ 
siderable revolution in natural history. Systematists 
will be able to pursue their labours as at present; but 
they will not be incessantly haunted by the shadowy 
doubt whether this or that form be in essence a species. 
This I feel sure, and I speak after experience, will be 
no slight relief. The endless disputes whether or not 
some fifty species of British brambles are true species 
will cease. Systematists will have only to decide (not 
that this will be easy) whether any form be sufficiently 
constant and distinct from other forms, to be capable 
of definition ; and if definable, whether the differences 
be sufficiently important to deserve a specific name. 
This latter point will become a far more essential con¬ 
sideration than it is at present; for differences, how¬ 
ever slight, between any two forms, if not blended by 
intermediate gradations, are looked at by most natural¬ 
ists as sufficient to raise both forms to the rank of 
species. Hereafter we shall be compelled to acknow¬ 
ledge that the only distinction between species and 
well-marked varieties is, that the latter are known, 
or believed, to be connected at the present day by in¬ 
termediate gradations, whereas species were formerly 
thus connected. Hence, without rejecting the con¬ 
sideration of the present existence of intermediate gra¬ 
dations between any two forms, w^e shall be led to weigh 
more carefully and to value higher the actual amount 
of difference between them. It is quite possible that 
forms now generally acknowledged to be merely varie¬ 
ties may hereafter be thought worthy of specific names, 
as with the primrose and cowslip; and in this case 
scientific and common language will come into accord¬ 
ance. In short, we shall have to treat species in the 
same manner as those naturalists treat genera, who 
admit that genera are merely artificial combinations 
