278 
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.