MIND IN EVOLUTION 535 



allow themselves to be removed boclily from it before offer- 

 ing to fly." . . . The egg is kept constantly covered. 

 " They turn it round and round with the beak; they go to 

 the water to wet the breast feathers to keep it moist; they 

 shove one another aside, when the shifts are made, without 

 exposing the egg for any length of time." When we are 

 dealing with a big-brained effective organism like a Tern 

 we cannot help feeling that the description does not lose in 

 scientific accuracy by allowing a modicum of awareness. 



Another way in which some degree of intelligence may 

 have evolutionary import is in connection with habit-forming. 

 Many of the higher animals are born with very imperfect 

 capacities, but they eke this out by the rapid acquisition of 

 habits. Given an imperfect pecking-capacity, the adapta- 

 tion may become perfect by habituation. Now we do not 

 suppose that all habit-forming implies mental processes, but 

 we maintain that some* do, namely those which involve an 

 appreciation of the situation. It is said that batting and 

 bowling are hard intellectual exercises, involving a multitude 

 of rapid judgments. So it may be with some vitally im- 

 portant habits of animals; and survival is with the edu- 

 cable. 



Some interesting data bearing on our problem may be 

 obtained from a study of what may be called conventions 

 among social animals. Taking penguins again, a case where 

 independent observers confirm one another, we find that the 

 early incubatory task is very arduous, involving in the Adelie 

 penguin a minimum total abstinence from food of about 

 eighteen days and a maximum of twenty-eight. Later on, 

 the two parents relieve one another at frequent intervals, 

 and they have a good deal of what looks like ' fun '. To 

 get more time without leaving the young birds to be killed 



