THE ELEMENTS OF MIND 197 



than any other animals, and carnivora smell 

 better. Ruminants see, hear, and smell with 

 great acuteness. Fishes also see and hear well ; 

 and the wings of the bat are so exceedingly sen- 

 sitive that it will move about blindfolded and with 

 ears stopped with cotton almost as unerringly as 

 when aided by sight and sound. Insects have 

 smell, sight, and taste well developed, as is shown 

 by their keen appreciation of the colours, perfumes, 

 and flavours of flowers. They also hear. Stridu- 

 lation proves this. Worms have eyes and ears, 

 and land-leeches scent the approach of their prey 

 at a long distance. The starfish and the medusa 

 respond to all the five classes of stimuli which 

 affect the five senses of man, and nervous sub- 

 stance is found in all animeJs above the sponge. 



Memory is the power of retaining or recognising 

 past states of consciousness. The pov/er to retain 

 impressions follows in origin close upon the power 

 to receive impressions. Memory is the historic 

 faculty of the mind — the power of the mind to 

 store up its experiences — and is found in nearly 

 all animals. The lowly limpet, whose world is a 

 seaside rock, will come back from its little roam- 

 ings time after time to the same rude lodge from 

 which it set out. Bees remember where they get 

 honey or sugar months afterwards, and when it is 

 necessary will sometimes go back to the old home 

 hive which they left the year before. Ants retrace 

 their steps after making long journeys from their 

 nest, and are able in some way to recognise their 

 friends after months of separation. The stickle- 



