90 Habit and Instinct. 



on the other hand, distasteful, we must avoid the error of 

 a too sweeping generalization. No doubt there may be 

 cases in which instinctive fear is evoked at the sight of 

 particular objects of alarm. To deny this would be going 

 beyond the evidence, and would savour strongly of dog- 

 matizing on negative premises. Where tradition is neces- 

 sarily excluded, as seemingly is the case with the megapodes, 

 it may be that the instinctive avoidance of any rapidly 

 approaching animal, whether it be harmful or harmless, 

 is insufficient to guard the young from destruction; and 

 there may be ingrained in the megapode constitution 

 through natural selection a congenital fear of such animals. 

 We must now pass to the notes emitted by young birds. 

 Whatever may be the case with the elaborated song of 

 birds, which is regarded by Mr. C. A. Witchell and others 

 as for the most part the result of tradition and imitation, 

 there can be no question that the sounds emitted by many 

 young birds are truly instinctive, and that some of them 

 are fairly differentiated from the first. In domestic chicks 

 I could distinguish at least six notes. First the gentle 

 " piping," expressive of contentment, heard on taking the 

 little bird in one's hand. A further low note, a sort of 

 double sound, seems to be associated with extreme pleasure, 

 when, for example, one strokes the chick's back and 

 caresses it. Very characteristic and distinct is the danger 

 note — a sound difficult to describe, but readily recog- 

 nizable. This is heard on the second or -third day. If a 

 large humble-bee, a black beetle, a big worm, a lump of 

 sugar, or in fact anything largish or strange, be thrown 

 to the chicks, the danger note is at once heard. Then 

 there is the cheeping, piping sound, expressive apparently 

 of wanting something. It generally ceases when one goes 

 to them and throws some grain, or even stands near them. 

 My chicks were accustomed to my presence in the room, 



