56 ANIMAL INSTINCT AND INTELLIGENCE 
And a convincing proof of the power of profiting by experience 
which constitutes intelligence is given in a letter of Dr. Peckham’s, 
quoted by Lloyd Morgan (in Anzmal Behaviour), in reference to 
a species (Sphex ichneumonea) which preys upon grasshoppers, and 
after leaving them a short time while she makes an excursion into 
the nest, returns and drags them in by their feelers. One individual, 
being several times thwarted in her storing work by removal of 
the victim to a short distance when she was in the nest, soon 
learnt the inadvisability of losing sight of her booty, and either at 
once dragged it into the hole or, straddling over it, substituted 
pushing for pulling. 
One of the most remarkable points about the nesting-instinct 
in so many solitary insects is the elaborate provision made for the 
welfare of offspring which will never be seen, and which commonly 
require food of quite different nature from that taken by the adult. 
The parent would seem to be urged on by irresistible impulses, 
and can hardly be supposed to realize the meaning of its work, 
except perhaps in a very dim sort of way. Butterflies and Moths 
illustrate the food-question very clearly. It is true that they do 
not construct and store nests, like the solitary wasps just mentioned, 
but they instinctively lay their eggs on special sorts of plant, upon 
the leaves of which their voracious offspring are destined to feed. 
A Peacock Butterfly (Vanessa Jo), for example, selects a nettle 
for the purpose, but her own food consists of nectar drawn from 
the recesses of flowers by means of suctorial mouth-parts, differing 
greatly from the powerful biting jaws of the leaf-eating caterpillar. 
It is almost impossible to believe that remembrance of her own 
larval days guides to the choice of a suitable place for egg-laying, 
for the caterpillar is converted into the adult by a series of revolu- 
tionary changes which amount to reconstruction. 
INSTINCT AND INTELLIGENCE IN Mottuscs (Mottusca).—Com- 
paratively few observations have been made upon the members of 
this group, some of which are very highly organized. Several 
good illustrations of both instinct and intelligence have, however, 
been recorded. 
The Octopus is one of the highest Molluscs, and appears to 
be a very intelligent creature. Schneider saw a young one seize 
a hermit-crab and then let it go, being stung by the zoophytes 
covering its shell. For some time at least this individual was 
observed to avoid hermit-crabs, having learnt to associate them 
