4 i 8 NATURE AND NURTURE 



688. Do purely instinctive animals sleep ? If they do, what is 

 the faculty that slumbers ? When they rest, as a fly in darkness, 

 and hardly any stimulus awakens their senses, are they unconscious 

 in a truer sense than we are during sleep? Or do they also 

 see visions ? Our visions are supplied by a more or less paralysed 

 memory ; what supplies their visions, if they have any ? Most of 

 the experiences stored in our memories are acquired through the 

 sense of sight. Is the fact that all animals with well developed 

 memories close their eyes during sleep connected with the fact 

 that their memories need rest ? It is true that the eyes of such 

 animals are especially vulnerable, but that peculiarity may be the 

 effect not the cause of the fact that eyes are covered by eyelids. 

 Apparently the eyes of insects see well enough ; and yet they are 

 not protected. 



689. Many insects, for example solitary wasps, are not pro- 

 tected during the beginnings of conscious life by their parents. 

 Therefore, of necessity, they are fully or almost fully equipped for 

 the battle of life by instinct. Nevertheless they are able to return 

 burdened with loads of food to the cells in which they have de- 

 posited their eggs. By what means do they find the road by 

 instinct or memory? The word memory is used in two senses, 

 one of which implies recollection, and the other bearing in mind. 

 We recollect when we recall an experience which was formerly in 

 consciousness but has passed out of it ; we bear in mind when we 

 keep an experience in consciousness. Thus I recollect a blow if, 

 after the memory of it has passed out of consciousness, a sight of 

 my opponent recalls the experience. I bear in mind if I continue 

 to dwell on the experience after having been struck. Probably 

 the kind of memory which is absent in purely instinctive animals 

 is the power of storing experiences so that they may be recalled. 

 Therefore it is possible that the wasp may instinctively bear in 

 mind, during all the vicissitudes of her hunt for food, the situation 

 of her nest ; in which case, she is, like higher animals, able to 

 attend to more than one thing at a time. On the other hand, if 

 she recalls the situation of her nest, of which she was previously 

 unmindful, she possesses a true memory ; but in that case, since 

 she is very incapable of learning other things J she has a memory 



with the lower, the more anciently evolved. The interpretation of this appears 

 to be that intoxication, like sleep, is a kind of paralysis by which the memory in 

 particular is affected. The highest faculties and the most skilful actions are those 

 which depend on the greatest amount of stored experience. The ' brute ' muscular 

 strength and the innate mental and nervous characters (instincts and reflexes) 

 are relatively little affected. l See Lubbock, Ants, Bees, and Wasps. 



