340 THE BIOLOGY OF BIRDS 



into the very earth itself, with nothing to show the presence 

 of hfe but their httle black, beady eyes. As long as the 

 danger remains imminent, the parents keep up an incessant 

 chuck-chucking, and the chicks remain absolutely still and 

 motionless. ... A chick that is only two or three hours 

 old will * squat ' at the warning cry, with the same celerity 

 and certainty as a chick of three or four weeks. It can be 

 no question of learning by experience and parental training. 

 It will squat at that cry, and at that cry only, though not from 

 any knowledge of the safety so acquired. Partridges reared 

 under a hen never squat, although danger is threatening, 

 and the foster-mother is clucking in a dreadful fluster. . . . 

 The necessary stimulus is absent, and that stimulus is sup- 

 plied by one particular cry of the parents and nothing 

 else " (F. M. Ogilvie, 1920)!' 



Intelligence Co-operating with Instinct. — Professor Lloyd 

 Morgan reared two moorhens in isolation from their 

 kindred, and watched them almost from hour to hour. 

 They swam instinctively, but they would not dive, either 

 in a large bath or in a stream, and diving is swimming with 

 a difference. One of these moorhens, about nine weeks 

 old, was swimming one day in a pool at the bend of a stream 

 in Yorkshire, when a puppy came barking down the bank 

 and made an awkward feint towards the young bird. " In 

 a moment the moorhen dived, disappeared from view and 

 soon partially reappeared, his head just peeping above the 

 water beneath the overhanging bank." This was the first 

 time the bird had dived, and yet its performance was 

 absolutely true to type. There can be little doubt that in 

 this case we have to recognise three factors : (i) the young 

 moorhen had a hereditary capacity for swimming and another 

 for diving ; (2) the young moorhen had enjoyed about two 

 months of swimming experience, which may have counted 

 for something ; hut (3) the bird saw and heard the dog, 

 was emotionally excited, and did to some extent intelligently 

 appreciate a novel and meaningful situation. Intelligence 

 co-operated with instinct and the young moorhen dived 

 appropriately. 



