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was found by far the most successful method, and was inherited like
the tendency of a bull-dog to pin the nose of a bull, or of a ferret to.
bite the cerebellum (of a rabbit?). It would not be a very great step
in advance to prick the ganglion of its prey only slightly, and thus to
give its larvae fresh meat instead of only dried meat.”
Commenting on this, Mr. Romanes says:—
“ Here, by the way, we have an excellent instance of the difficulty
which we so often encounter in the domain of instinct, when we
relinquish the so-called Lamarckian principle of the inheritance of
acquired characters. The hypothesis in question goes upon the
supposition that some of the ancestors of the sphex were intelligent
enough to notice the peculiar effects which followed upon stinging
insects or caterpillars in the particular regions occupied by nerve-
centres, and that, in consequence of being habitually guided by their
intelligence to sting in these particular regions, their action became
hereditary—i.e., instinctive. But if, in accordance with post-Dar
winian theory, we relinquish this possible guidance by intelligence,
and suppose that the whole of this wonderful instinct was built up by
Natural Selection waiting for congenital—i.e., fortuitous—variations
in the direction of a propensity to sting, say, the nine nerve-centres
of a caterpillar—then it surely becomes inconceivable that such
an instinct should ever have been developed at all.”—{Nature,
vol. xxxix, ft. 77.)
And yet this is the same advocate who regards the realm
of instinct as the favourite sphere for the exhibition of the
action of Natural Selection.
It only remains for me to show that the evolution of
instinct, apart from the interposition of human intelligence,
as it is depicted by Mr. Darwin, is not possible. It is
worthy of notice, at the outset, that Mr. Darwin does not
define the term instinct. “I will not attempt any definition
of instinct.”* Having given a definition of what is usually
said to be instinctive, he adds : “ but I could show that
none of these characteristics is universal.” It is, however,
important to observe that he adopts the dictum of Pierre
Huber, to the effect that a little dose of judgment or
reason often comes into play even with animals low in the
* Origin of Species, p. 20J.