Craig, Expressions of Emotion in Pigeons. 69 



long period — even weeks — of acquaintanceship. But once the birds 

 have had their attention concentrated on each other and have become 

 affectionate, the business of breeding proceeds smoothly and rapidly. 



C. Beginning of the Brood Cycle, 



In the preparation for a brood of young, whether it be the first 

 brood of the season or a later brood, there is always first a period 

 such as has been described, in which the male by means of the kah- 

 of-excitement, the bowing-coo, charging upon, the female and even 

 pecking her severely, gains a mastery over the female that draws her 

 attention to himself to the exclusion of all other males which may 

 come ill sight or which may be surviving in the female's memory. 

 The female on her part submits herself to the male and draws his 

 attention to her. And both birds become worked up to a state of 

 tense sexual excitement. This period is ahvays followed by a second 

 period in which the excitement, venting itself in copulation and in 

 work upon the nest, becomes less violent, though perhaps not less 

 powerful. The charge and the kah-of-excitement fall to a very low 

 ebl>, and even the bowing-coo is used much less than at first ; but the 

 perch-coo and the nest-call are in frequent requisition. 



Copulation is repeated a great number of times, there being many 

 repetitions per day and continuance for a number of days. It is 

 continued until near the time when the first Qs^g is laid ; and some- 

 times even after the first egg is laid. The number of days of copula- 

 tion seems to be ordinarily four or five ; but there is at hand as I 

 write, a pair of l)irds still continuing a series which they began 

 fifteen days ago. The number of copulations or attem]:»ts at copula- 

 tion in one daj^, I have never determined under normal conditions. 

 In certain abnormal experimental conditions, devised for another 

 purpose, I counted on several different days from twelve to fifteen 

 attempts per day. I should think that even in normal cage conditions 

 the number of attempts might be equally great. 



The first day of copulation is a day of high excitement, and the 

 divers expressions of this excitement may be divided into two classes ; 

 namely, those that occur through a great part of the day in general, 



