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 Animal 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 lo), 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 MOLLUSCS (MOLLUSCA). 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 



