INSTINCT AND REASON. 681 
not only have feelings, intelligence, and volition, but are 
possibly, in a very slight degree, self-conscious. The fact 
that animals exercise discrimination in the selection of 
food, in the choice of a flower or object of one color in 
preference to unother, in perceiving likeness or unlikeness in 
two objects, indicates that they can exercise the power of 
intelligent discrimination, as has been said by Mr. G. H. 
Lewes :* ‘‘ When there is no alternative open to an action 
it is impulsive ; when there is, or originally was, an alter- 
native, the action is instinctive ; where there are alterna- 
tives which may still determine the action, and the choice 
is free, we call the action intelligent.” 
Indeed, animals have the principle of similarity strongly 
developed. It is the bond that holds together the social or- 
ganizations of such insects as live in colonies, and such fish, 
birds, or mammals as go in schools, flocks, or herds. Were 
it not for this mental quality some species would tend to 
die out. 
Animals possess memory, which consists in storing up in 
the mind the results of external impressions, so that they 
are enabled to perceive the points of resemblance or differ- 
ence between two objects, after having been out of sight of 
them for a greater or less length of time. Bain defines 
memory, acquisition or retention, as ‘‘ being the power of 
continuing in the mind impressions that are no longer stim- 
ulated by the same agent, and of recalling them afterward 
by purely mental forces.”’ 
With the aid of memory, birds make their migrations, 
bees and ants find their way back to their nests. As we 
have elsewhere said, ‘‘ No automaton could find its way 
back to a point from which it had once started, however 
well the machine had been originally wound up. Nor does 
the common notion of an inflexible instinct meet the case. 
Memory is often due to a repetition of certain experiences, 
and experiences lay the foundation for instinctive acts ; it 
is the sum of these inherited experiences which make up 
the total which passes under the name of instinct.’’} 
* Article on Instinct in Nature, April 10th, 1873. 
+ Half Hours with Insects, p. 374. 
