n the Continent and
the Azores, or Madeira, or the Canaries, or Ireland, be sufficient? It must
be admitted that many forms, considered by highly-competent judges as
varieties, have so perfectly the character of species that they are ranked
by other highly-competent judges as good and true species. But to discuss
whether they are rightly called species or varieties, before any definition
of these terms has been generally accepted, is vainly to beat the air.

Many of the cases of strongly-marked varieties or doubtful species well
deserve consideration; for several interesting lines of argument, from
geographical distribution, analogical variation, hybridism, &c., have been
brought to bear on the attempt to determine their rank. I will here give
only a single instance,--the well-known one of the primrose and cowslip, or
Primula vulgaris and veris. These plants differ considerably in appearance;
they have a different flavour, and emit a different odour; they flower at
slightly different periods; they grow in somewhat different stations; they
ascend mountains to different heights; they have different geographical
ranges; and lastly, according to very numerous experiments made during
several years by {50} that most careful observer Gaertner, they can be
crossed only with much difficulty. We could hardly wish for better evidence
of the two forms being specifically distinct. On the other hand, they are
united by many intermediate links, and it is very doubtful whether these
links are hybrids; and there is, as it seems to me, an overwhelming amount
of experimental evidence, showing that they descend from common parents,
and consequently must be ranked as varieties.

Close investigation, in most cases, will bring naturalists to an agreement
how to rank doubtful forms. Yet it must be confessed that it is in the
best-known countries that we find the greatest number of forms of doubtful
value. I have been struck with the fact, that if any animal or plant in a
state of nature be highly useful to man, or from any cause closely attract
his attention, varieties of it will almost universally be found recorded.
These varieties, moreover, will be often ranked by some authors as species.
Look at the common oak, how closely it has been studied; yet a German
author makes more than a dozen species out of forms, which are very
generally considered as varieties; and in this country the highest
botanical authorities and practical men can be quote