Craig, Expressions of Emotion in Pigeons. 79 



Professor AVbitinaii has kept blond ring-doves till they were 

 about ten years old. In one such case be knew pretty definitely that 

 the bird's death was due to causes other than old age. Yet he thinks 

 that he has observed somewhat of a decline in t-be breeding powers in 

 a bird about ten years old. 



Summary of the Life-History. 

 A'. Beginning of the life cycle. 



The voice of the young ring-dove is heard the first day, and is 

 useful to induce the parents to commence feeding (page 55). 



The voice of the growing young is useful to cause the parents to 

 give a sufficient amount of food, and to continue feeding until the 

 young one is able to feed itself (page 57 ). 



Fear begins to be shown as soon as the young have the full use of 

 their eyes (page 55). 



Alarm develops somewhat later, 12th to 14th day (page 59). 



The kah appears often on the 27th day (page 60). 



The charge appears on the 27th day or later (page 65). 



The coo appears from the 27th to the 47th day (page 62). It 

 is at first very imperfect, and develops very slowly to the adult form. 



Development of the voice is of two sorts which may be referred 

 to two causes ; namely, development of the syrinx or vocal apparatus, 

 and development of the nervous system (page 01). 



The young often give cries at the suggestion of the parents, but 

 they do not imitate the cries of the parents (page 64). 



B'. Beginning of the annual cycle. 



The elaborate cooing and other performances of the spring season 

 serve to proclaim the sex of each bird (there being no markings 

 distinctive of sex), to bring the birds together in pairs, and to unite 

 each pair by a firm bond (pages 66-69). 



C Beginning of the brood cycle. 



The male and the female, by mutual stimulation and self-stimu- 

 lation, work up a pitch of excitement sufficient to start them on the 

 arduous, month-long labors of the brood cycle (page 69). 



