Natural History 445 



life." There is often an extraordinary subtlety as well as beauty 

 in their habits. They are big-brained animals, and the senses of 

 sight and hearing are developed to great perfection. 



The question is how much in the behaviour of birds we must 

 ascribe to instinctive endowment, that is, to inborn impulsions 

 or hereditary nervous predispositions, and to what extent must 

 we credit the bird with intelligent learning? When a young 

 moorhen swims deftly the first time it touches the water, or dives 

 perfectly when the fit and proper stimulus is forthcoming, we 

 interpret this as instinctive. Its physiological side is a con- 

 catenation of reflex actions. Its psychological side is inborn 

 impulse and endeavour. Similarly, when an unhatched lapwing 

 utters its characteristic call-note "peewit" from within the egg, 

 we say this is instinctive independent of instruction, learning, 

 or imitation. 



But a different note is sounded in the behaviour of the 

 Greek eagle, which lets the tortoise fall on the rocks from a 

 great height, so that the carapace is broken, or in the similar 

 device of the Rook that lifts the freshwater mussel and lets it 

 fall on the riverside stones. The Herring-Gull sometimes lifts 

 the sea-urchin, or the clam, in its bill, and lets it fall on the 

 shingle, so that the shells are broken. Without necessarily sup- 

 posing that these birds thought out the expedient, we can hardly 

 avoid the conclusion that they utilise the discovery intelligently. 

 In many cases the bird must be credited with an appreciation of 

 circumstances, with an awareness of what is significant, and with 

 a capacity for learning. The young chick's capacity for rapidly 

 learning simple lessons, mostly associations, has been proved up 

 to the hilt by many experiments. 



"In the quiet of the wood one sometimes hears the song- 

 thrush breaking snail shells on its stone anvil, and one may 

 easily find the telltale evidences of its appetite. Is this habit, 

 which comes so near using a tool, an inborn gift or has it to be 

 learned? The answer is given by Miss Frances Pitt in her 



