54 Journal of Comparative Neurology and Psychology. 



season, since it is occupied with the rearing of several successive 

 broods, is divided into as many brood cycles, each consisting of several 

 days of love-making and nest-building, fourteen days of sitting on 

 the eggs, and at least as many days of caring for the young. (D) 

 At the time of brooding, the birds' activities fall into a very definite 

 round, repeated daily, constituting the daily cycle. Of course the 

 dove's whole life is divided into daily cycles of a sort, because the 

 birds invariably roost through the night and do all their work in 

 the day time. But the most specialized daily program, the one 

 which will therefore be described in this paper as a type, is the daily 

 program at the time of brooding. 



These four cycles will best be treated in the order in which they 

 come and go in the dove's life. Accordingly, the order of the treat- 

 ment Avill be as follows: — 



A'. Beeinnina' of the life cvcle. 



Co o 



B'. Beginning of the annual cycle. 



C. Beginning of the brood cycle. 



D. The daily cycle. 

 C/'. The brood cycle, continued. 

 B". The annual cycle, continued. 

 A". The life cycle, continued. 



A'. Beginni2\^g of the Life Cycle. 

 The day of hatching. — When hatched, the pigeon is a little blind 

 and naked body, able to slightly raise a shaking and swaying head 

 and open its bill to receive the food regurgitated by the parent, and 

 just able to drag itself slowly, by using the feet, from one position 

 to another in the nest. When a parent wishes to feed a young one, 

 she (or he) puts her lull down to the young one and gently touches 

 its head, or takes hold of its bill. Then the young one raises its 

 head in its shaky and indefinite way and after a number of random 

 movements gets its bill into that of the parent and is fed. It seems as 

 if sometimes the mere movement of the mother in raising her body 

 from the young is sufiicient to cause it to raise its head for food. If 

 the young be touched by the hand at this time their response is either 



