|
ranked as species, but which he considers as so closely allied to other species as to be of doubtful value: these 63 reputed species range on an average over
of the provinces into which Mr. Watson has divided Great Britain. Now, in this same
53 acknowledged varieties are recorded, and these range over
whereas, the species to which these varieties belong range over
provinces. So that the acknowledged varieties have
nearly the same restricted average range, as have
closely allied forms, marked for me by Mr. Watson as doubtful species, but which are almost universally ranked by British botanists as good and true species. →
|
| Finally,
varieties
→OMIT
cannot be distinguished from
by the discovery of intermediate
→them together, and the occurrence of such links does not affect the character of the forms which they connect; and except,
by a certain
of
→for
two forms, if differing very little, are generally ranked as varieties, notwithstanding that
→intermediate linking forms have not been discovered;
but the amount of difference considered necessary to give to
forms the rank of species
→is quite indefinite. In genera having more than the average number of species in any country, the species of these genera have more than the average number of varieties. In large genera the species are apt to be closely, but
allied together, forming little clusters round
Species very closely allied to other species apparently have restricted ranges. In all these
respects the species of large genera present a strong analogy with varieties. And we can clearly understand these analogies, if species
once existed
varieties, and
thus
whereas, these analogies are
|
