H.C.
Watson, to whom I am much indebted for valuable advice and assistance
on this subject, soon convinced me that there were many difficulties, as
did subsequently Dr. Hooker, even in stronger terms. I shall reserve for
a future work the discussion of these difficulties, and the tables of
the proportional numbers of the varying species. Dr. Hooker permits me
to add that after having carefully read my manuscript, and examined
the tables, he thinks that the following statements are fairly well
established. The whole subject, however, treated as it necessarily here
is with much brevity, is rather perplexing, and allusions cannot be
avoided to the "struggle for existence," "divergence of character," and
other questions, hereafter to be discussed.

Alphonse de Candolle and others have shown that plants which have
very wide ranges generally present varieties; and this might have been
expected, as they are exposed to diverse physical conditions, and as
they come into competition (which, as we shall hereafter see, is a far
more important circumstance) with different sets of organic beings. But
my tables further show that, in any limited country, the species which
are the most common, that is abound most in individuals, and the species
which are most widely diffused within their own country (and this is a
different consideration from wide range, and to a certain extent from
commonness), oftenest give rise to varieties sufficiently well-marked to
have been recorded in botanical works. Hence it is the most flourishing,
or, as they may be called, the dominant species--those which range
widely, are the most diffused in their own country, and are the most
numerous in individuals--which oftenest produce well-marked varieties,
or, as I consider them, incipient species. And this, perhaps, might have
been anticipated; for, as varieties, in order to become in any degree
permanent, necessarily have to struggle with the other inhabitants of
the country, the species which are already dominant will be the most
likely to yield offspring, which, though in some slight degree modified,
still inherit those advantages that enabled their parents to become
dominant over their compatriots. In these remarks on predominence, it
should be understood that reference is made only to the forms which come
into competition with each other, and more especially to the members
of the same genus or class having nearly similar habits of life. With
respect to the n