224 The Outline of Science 



capacities, but eminently "educable," and the "little-brain" type, 

 say, of ants and bees, richly endowed with instinctive capacities, 

 but very far from being quick or glad to learn. We owe it to 

 Sir Ray Lankester to have made it clear that these two types of 

 brain are, as it were, on different tacks of evolution, and should 

 not be directly pitted against one another. The "little-brain" 

 type makes for a climax in the ant, where instinctive behaviour 

 reaches a high degree of perfection; the "big-brain" type reaches 

 its climax in horse and dog, in elephant and monkey. The par- 

 ticular interest that attaches to the behaviour of birds is in the 

 combination of a good deal of instinct with a great deal of intel- 

 ligent learning. This is well illustrated when birds make a nest 

 out of new materials or in some quite novel situation. It is 

 clearly seen when birds turn to some new kind of food, like the 

 Kea parrot, which attacks the sheep in New Zealand. 



Some young woodpeckers are quite clever in opening fir 

 cones to get at the seeds, and this might be hastily referred to a 

 well-defined hereditary capacity. But the facts are that the 

 parents bring their young ones first the seeds themselves, then 

 partly opened cones, and then intact ones. There is an educative 

 process, and so it is in scores of cases. 



Using their Wits 



When the Greek eagle lifts the Greek tortoise in its talons, 

 and lets it fall from a height so that the strong carapace is broken 

 and the flesh exposed, it is making intelligent use of an expedient. 

 Whether it discovered the expedient by experimenting, as is 

 possible, or by chance, as is more likely, it uses it intelligently. 

 In the same way herring-gulls lift sea-urchins and clams in their 

 bills, and let them fall on the rocks so that the shells are broken. 

 In the same way rooks deal with freshwater mussels. 



The Thrush's Anvil 



A very instructive case is the behaviour of the song-thrush 

 when it takes a wood-snail in its beak and hammers it against a 



