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It seems to me that the cases which have been investi
gated do not go to show that unintelligent habits of a
non-adaptive character have arisen de novo. Either they
are intelligent and adaptive, or they have lost those
characteristics through change of circumstances. If, then,
we cannot find illustrations of such instincts, we need
not exercise our imagination in picturing how Natural
Selection would act if change of circumstances made
these variations useful.
(5) In the fifth place, it is contended that certain instincts
must have been developed apart from intelligence, because
animals sometimes perform actions the prospective utility
of which they cannot possibly understand. But it may be
doubted whether this blindness always exists, or, at any
rate, is so absolute as is sometimes supposed. Take as an
illustration the case of the butterfly which lays its eggs on
the cabbage-leaf. Dr. Duncan, in his lecture on Insect
Metamorphosis, says :—
“ Does the butterfly remember its existence as a gormandising
caterpillar and therefore retain some notion of the propriety of laying
eggs over cabbages ? Does the Odynerus fly remember its under
ground life and obey some impulse to provide the unseen offspring
with food different to that which she loves? It is possible; and, as
nothing is too wonderful for psychologists, there may be something in
the suggestion.”—(Nature. vol. vii., p. jj.)
Very wonderful it would be if the butterfly had never
had any personal experience of cabbage. But in point of
fact, what have been its antecedents ? Before the brief
career of its imago condition it has spent its time in
gorging and in sleeping. Again and again it has burst the
buttons of its jacket and a new jacket has been provided
—eating meanwhile nothing but cabbage. As the sense of
smell is strong in insects, and particularly useful with us in
exciting old memories, I can see no reason why this two