n of growth. And, if
so, the possibility of originally useless characters happening in some
cases to become, by increased development, useful characters, is
correspondingly increased. Among a hundred varietal or specific
characters which are directly produced in as many different species by a
change of climate, for example, some five or six may be _potentially_
useful: that is to say, characters thus adventitiously produced in an
incipient form may only require to be further developed by a continuance
of the same causes as first originated them, in order that some
percentage of the whole number shall become of some degree of use. Those
professed followers of Darwin, therefore, who without any reason--or, as
it appears to me, against all reason--deny the possibility of useless
specific characters in any case or in any degree (unless correlated with
useful characters), are playing into the hands of Darwin's critics by
indirectly countenancing the difficulty which we are now considering.
For, if correlation of growth is unreasonably supposed to be the only
possible cause of the origin of incipient structures which are not
useful from the first moment of their inception, clearly the field is
greatly narrowed as regards the occurrence of incipient characters
sufficient in amount--and, still more, in constancy of appearance and
persistency of transmission--to admit of furnishing material for the
working of natural selection. But in the measure that incipient
characters--whether varietal or specific--are recognised as not always
or "necessarily" useful from the moment of their inception, and yet
capable of being developed to a certain extent by the causes which first
led to their occurrence, in that measure is this line of criticism
closed. For of all the variations which thus occur, it is only those
which afterwards prove of any use that are laid hold upon and wrought up
by natural selection into adaptive structures, or working organs. And,
therefore, what we see in organic nature is the net outcome of the
development of all the happy chances. So it comes that the appearance
presented by organic nature as a whole is that of a continual fulfilment
of structural prophecies, when, in point of fact, if we had a similar
record of all the other variations it would be seen that possibly not
one such prophecy in a thousand is ever destined to be fulfilled.

* * * * *

Here, then, I feel justified in fi