MIND IN EVOLUTION 535 



allow themselves to be removed bodily 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 



