50 'Journal of Comparative Neurology and Psychology. 



such a way as to convey a feeling of intense excitement. The ex- 

 pression of excitement is dne to the entire character of the coo and 

 cannot be completely analyzed. However, it may be said that the 

 sound is, for one thing, louder than that of the perch-coo. It is 

 usually higher in pitch, with the changes in pitch greater. Haste, 

 as if the bird were in a great hurry to express all its excitement, 

 invariably characterizes this coo, notwithstanding the fact that the 

 total duration of the coo may be no less than that of the perch-coo. 

 1'lie series of bowing-coos are somewhat longer than those of perch- 

 coos; on a certain summer's morning, the series varied from 4 to 10 

 coos each, averaging 6 and a fraction ; and, whereas the perch-coo 

 may be given singly, or only two or three times in succession, I have 

 no record of the bowing-coo being given less than four times in suc- 

 cession save in case of the bird being disturbed when in f\dl opei- 

 ation. 



The following are good examples of the bowing-coo. The guttural 

 "^0 o" at the end is conspicuous, and in extreme cases it is quite loud, 

 this being highly characteristic of the l)Owing-coo. 



NO. 19. 



^7^ ^. ! 



^ )-^ i rr i i r 



•m'^ 



^ 



cook coorr roo go o 



Time : 3 eroteliets per second. 



N0.20, 



1^^ 



Ss 



s 



J _ 'J l^X 



cook coorr roo qoo 



Time: about 4 crotchets per second. (The whole lasts 2 seconds -(-). Accom- 

 panied by a more perfect bow than the preceding. 



These two coos were given by a bird with an unusually clear, re- 

 sounding voice, a bird who cooed deliberately and musically. But 

 in many individuals the voice, instead of sounding such a deep rich 



