48 Journal of Comparative Neurology and Psychology. 



Fig. 3), braces its muscles for the effort, and draws a deep breath; 

 then, during the expulsion of the breath, the expelled air fills the 

 crop, causing a great round swelling of the fore neck, oxtt^nding to the 

 sides of the neck, the throat, and the upper breast. In the interval 

 between coos, the swelled crop subsides somewhat, and during each 

 coo it is again blown out to the fullest extent. 



The music of the perch-coo is as described for the coos in general. 

 The perch-coo may be taken as a mean, from which the bowing-coo 

 departs in one direction, the nest-call in another. The perch-coo is 

 often given singly, but usually in series. The number of coos in a 

 series, recorded throughout the early morning (if a certain summer 

 day, varied from ?> to 9, averaging 6. During the evening of a simi- 

 lar day, the number in a series varied from 2 to 5, averaging 4. 

 The following are typical examples of the perch-coo of the male. 



NO.15 







NO.I6. 



i ^'^ n^'prir^ - i N iiln'^fria 



cook coorr roo goo 



^ - _ _ E" 

 cook coorr roo qbo 



The perch-coo of the female differs from that of the male, as has 

 already been stated for the coos of the female in general (p. 46), in 

 being less loud, and poorer in both quality and expression. With 

 regard to the perch-coo in particular, it must be added that the female 

 often omits the guttural ''go o" at the end, and even when she does 

 give the guttural it is usually reduced to one'syllab'e, sounding like 

 "wah." 



N0.I7. 



NO. 18. 



=^ 



E 



^ 



m 



<a p q 



:. - ' - r -. _ "t^ 



cook coorr roo cook coorr roo wah cook coorr roo wah 



(II) The bowing-coo. The bowing-coo is given on the same oc- 

 casions with the kah-of-excitement and the charge. These three 



