554 LIFE : OUTLINES OF GENERAL BIOLOGY 



than others. A recent modification of the experiment by Mr. H. 

 Guthrie-Smitli consi.sted in putting the egg on the margin of the 

 nest so that the bird's .settling down made it move a little inwards. 

 That movement, or perhaps the contact, seemed to pull some trigger, 

 perhaps of an instinct to sit on the eggs and not merely upon the 

 nest, for the bird proceeded to adjust her body until the egg was 

 moved into its proper place, where it could be effectively incubated. 

 More experiments with what is sometimes mistakenly called "the 

 hopelessly stupid" might throw some further light on the contra.st 

 between instinctive and intelligent behaviour. 



EDUCATION IN ANIMALS.— In some birds and mammals it has 

 been observed that the young receive parental education. This varies 

 in its detail in different cases, for it may be little more than the supply- 

 ing of a liberating stimulus or an incentive to action, while in more 

 complicated expressions the education amounts to careful training 

 in the way in which certain things should be done. The parental 

 instruction is advantageous in lessening the time required if dexterity 

 has to be learned by individual experiment. It also lessens the risks 

 of the self-educating method. Moreover, in all probability, there is 

 some profitable handing-on of the gains of parental experience — a 

 simple form of extra-organismal heritage. 



To begin with simple cases, we may notice how a dabchick, with 

 its young ones on its back, depresses itself in the water and thus 

 forces them to begin to learn to find their way about. A grebe has 

 been seen ducking one of its offspring, as if accustoming it to immer- 

 sion. The Great Crested Grebe often dives after fish while carrying 

 the young ones on its back, and they soon learn their lesson. Although 

 young birds do not require to be taught to fly, the parents may 

 force or encourage them to make a beginning, sometimes tempting 

 them with food. A guillemot may push its young one off the brooding 

 ledge on to a slope which leads steeply to the sea. Mr. Coward notes 

 that "a more usual method is for the old bird to seize the unfortunate 

 by one wing, and, flying out with it until clear of surf and rocks, 

 let it drop". The young bird oi:>ens its wings and flutters. It takes 

 its first flight diagonally down to the sea, where it also takes its 

 first, somewhat compulsory, dive, and follows this by beginning to 

 swim. It is waited on by its parents, or by one of them, and gets 

 some help with its meals until it is able to fend for itself. There are 

 several similar cases well documented. 



Some forms of education take the form of graduated meals, as 

 has been observed in birds of prey, like the Peregrine Falcon and 

 the Golden Eagle. From carefully prepared pieces of flesh, to begin 

 with, the nestlings are gradually trained to tackle more or less 

 intact booty. L. T. Hobhouse refers to the expertness shown by some 

 young woodpeckers in getting at the seeds of fir-cones, but he points 



