SENSES, INSTINCTS, AND INTELLIGENCE 339 



aquatic life. She takes them on her back and then sinks 

 beneath the water, leaving them gently afloat. Among 

 guillemots and razorbills and other members of the auk 

 family there is often some coercion in the early training, 

 and indeed the first plunge from the cliff into the sea would 

 try any creature's nerve ! 



Our first point, then, is that many effective things that 

 birds do are the expressions of innate predispositions of a very 

 definite kind, which result in pecking, scratching, swimming, 

 diving, flying, crouching, lying low and so on. But this 

 repertory is much more limited in birds than in creatures 

 like bees and wasps, which belong to the " little-brain " 

 line of evolution. Professor Lloyd Morgan found that his 

 chicks, incubated in the laboratory, paid no attention to 

 their mother's cluck when she was brought outside the door. 

 Although thirsty, and willing to drink from a moistened 

 finger-tip, they did not instinctively recognise water even 

 when they walked through a saucerful. Only when they 

 happened to peck their toes when standing in water did 

 they appreciate water as the stuff they wanted and raise 

 their bills up to the sky. And was not the limited character 

 of instinct clearly shown by the way in which they stuft'ed 

 their crops with " worms " of red worsted ? Evidently 

 they were missing their mother's teaching ! Limited as 

 they were, however, they learned with prodigious rapidity, 

 thus illustrating the deep difference between the " big 

 brain " type, relatively poorly endowed with instinctive 

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

 type, say, of ants and bees, very richly endowed with 

 instinctive capacities but far from being quick or glad to 

 learn. Not more than once or twice did the chicks experi- 

 ment with the red worsted ; not more than once or twice 

 did they try an unpalatable caterpillar. 



A good example of instinctive behaviour is seen in the 

 obedience of many young birds to the parent's danger note. 

 When suddenly threatened with danger the parent part- 

 ridges utter the warning cry, and the chicks " squat flat 

 on the ground, as if they were trying to squeeze themselves 



