n6 MIND IN EVOLUTION CHAP. 



removed, and thrown in again towards the close of the day. 

 Some of the chicks tried them once, but they were soon left. 

 The next day the young birds were given brown loopers and 

 green cabbage-moth caterpillars. These were approached with 

 some suspicion, but presently one chick ran off with a looper, 

 and was followed by others, one of which stole and ate it. In a 

 few minutes all the caterpillars were cleared off. Later in the 

 day they were given some more of these edible caterpillars, which 

 were eaten freely j and then some cinnabar larvae. One chick 

 ran, but checked himself, and, without touching the caterpillar, 

 wiped his bill a memory of the nasty taste being apparently 

 suggested by association at sight of the yellow-and-black cater- 

 pillar. Another seized one, and dropped it at once. A third 

 subsequently approached a cinnabar as it crawled along, gave the 

 danger note, and ran off. Then I threw in more edible cater- 

 pillars, which again were eaten freely. The chicks had thus 

 learnt to descriminate by sight between the nice and the nasty 

 caterpillars." * 



The inference from these observations seems clear 

 enough. The inhprifp^ fpnrlenrv of the chicks is to peck 

 to peck at " anything and everything, not too large/' 

 But experience very rapidly teaches that it is pleasant to 

 peck at Some things such as yolk of egg or cabbage-moth 

 caterpillars and very unpleasant to peck at others, such as 

 cinnabar caterpillars or bits of orange-peel. The tendency 

 to peck at the one sort of object is accordingly confirmed. 

 The tendency to peck at others is inhibited. And the 

 result is that pecking, from being an indiscriminate ten- 

 dency, becomes a definite mode of response to certain 

 objects. The instinctive tendency is regulated, narrowed, 

 and defined, as it becomes a habit in which experience has 

 played its part. 



This form of the action of experience is very widely dif- 

 fused in the animal kingdom, and is too simple to need 

 much further illustration. But I may note one or two cases 

 illustrating an important difference in one point. One in- 

 stance was sometimes enough to teach Mr. Lloyd Morgan'* 

 sharp little chicks. But the effect of the experience tends 

 to wear off with time. The chick that had learnt to re- 

 ject the cinnabar larva at one hour would perhaps try it 



1 Lloyd Morgan, Habit and Instinct, pp. 40-42. 



