ercrossing with allied forms. If it had been said that these
colour-differentiations were originated by some cause other than natural
selection (or, if by natural selection, still with regard to some
_previous_, instead of _prophetic_, "purpose"), and, when so "acquired,"
_then_ began to serve the "purpose" assigned, the argument would not
have involved the fallacy which we are now considering. But, as it
stands, the argument reverts to the teleology of pre-Darwinian days--or
the hypothesis of a "purpose" in the literal sense which sees the end
from the beginning, instead of a "purpose" in the metaphorical sense of
an adaptation that is evolved by the very modifications which subserve
it[33].

[32] _Darwinism_, pp. 218 and 227.

[33] Since the above was written Prof. Lloyd Morgan has published a
closely similar notice of the passage in question. "This language,"
he says, "seems to savour of teleology (that pitfall of the
evolutionist). The cart is put before the horse. The
recognition-marks were, I believe, not produced to prevent
intercrossing, but intercrossing has been prevented because of
preferential mating between individuals possessing special
recognition-marks. To miss this point is to miss an important
segregation-factor."--(_Animal Life and Intelligence_, p. 103.)
Again, on pp. 184-9, he furnishes an excellent discussion on the
whole subject of the fallacy alluded to in the text, and gives
illustrative quotations from other prominent Darwinians. I should
like to add that Darwin himself has nowhere fallen into this, or any
of the other fallacies, which are mentioned in the text.

* * * * *

Another very prevalent, and more deliberate, fallacy connected with the
theory of natural selection is, _that it follows deductively from the
theory itself_ that the principle of natural selection must be the sole
means of modification in all cases where modification is of an
_adaptive_ kind,--with the consequence that no other principle can ever
have been concerned in the production of structures or instincts which
are of any use to their possessors. Whether or not natural selection
actually has been the sole means of adaptive modification in the race,
as distinguished from the individual, is a question of biological
fact[34]; but it involves a grave error of reasoning to suppose that
this question can be answered deductively from