30 "Journal of Cojiiparative Neurology and Psychology. 



B." The seasonal cycle, continued 78 



The lapse of broocUng and loss of voice at the end of the breed- 

 ing season IS 



A" The life cycle, continued 7S 



The prime of life, and old age 78 



Sunnnary of the life-history 79 



Intkoductiox. 

 This study of the behavior of i^igeons was undertaken seven years 

 ago with intention^^'rs^, to describe the various sounds produced 

 by one type species of pigeon, and the bodily movements which in- 

 variably accompany the utterance of the sounds ; second, to compare 

 these with the sounds and movements of all the species in Professor 

 AVhitman's large collection of living pigeons; third, to throw light 

 upon any problems which seemed naturally to connect with the study 

 as it progressed. The present paper is drawn up to fulfill the first 

 of these intentions. It is a descriptive account of the vocal and 

 bodily expressions of emotion in one species chosen as a type. It 

 may make this first j^aper more valuable if I indicate briefly the 

 nature of the work by which it is to be followed. The following is a 

 brief outline of the whole. 



1. Description of the vocal and bodily expressions of emotion iii 

 the blond ring-dove. Life-history of this species, in so far as it 

 c(mcerns the use of voice and accompanying gesture (present paper). 



2. Comparison of the sounds and gestures of different species ; 

 showing specific characteristics, homologies, and the possibility of 

 voice and gesture throwing light on problems of phylogeny. 



3. Irdieritance. The forms of expression in jiigeons are strictly he- 

 reditary. They are not learned by imitation (coj^ying). In hybrids 

 the voice is intermediate, except when it is im])erfectly develo])ed. 



4. Variation. Comparative study shows that the vocal utter- 

 ances v^ary from group to group in a manner indicating detenninate 

 or orthogenetic variation. 



5. Selection. Pigeons are subject to sexual selection of a kind 

 more or less like that described by Hacker.^ But the theory of 



^Hacker, Valentin. Der Gesang der Vogel. .Tena, 19<)0. Hacker's state- 

 ment is an improvement upon that of Groos, in his "Die Spiele der Thiere," 

 Jena, 189G. 



