y8 'Journal of Comparative Neurology and Psychology. 



B". The Seasojn'al Cycle^ Contixued. 



Renewed efforts, as shown in cooing, kahing, nest-building, and 

 a host of other activities, are necessary to initiate each brood cycle. 

 If the birds be disinclined to effort, from any cause, such disin- 

 clination will delay or prevent the commencement of another brood 

 cycle. This is what happens in the molting season, beginning in the 

 latter part of August. There may be a decrease of breeding power, 

 especially in some pigeons, even before the molt; but most of the do- 

 mestic ring-doves retain ample breeding powers up to the time when 

 the molt begins to diminish their general vitality. The breeding 

 powers lost at this time are not regained, by the wald species, until 

 the following spring ; and though the domestic ring-dove may be bred 

 all through the autumn and winter, yet the frequency of repetitions 

 of the brood cycle is lessened, the health of the birds may suffer, 

 and it is evident that this extension of the breeding season is unna- 

 tural. Coincident with the lapse of lu'eeding propensity, in all spe- 

 cies of pigeons, is a loss of voice, a loss especially of the more emo- 

 tional, more musical notes. The loss of voice is not so conspicuous 

 in the domesticated and unnatural ring-dove. The loss of song is 

 not complete even in most of the wild species, for their coos may be 

 heard at irregular inter\^als through the months of September and 

 October at least; but the coo at this time is in some cases notably 

 different from that of the ]ireedino--season. And thouo-h the sone's 

 may be given thus sporadically, their sum total is exceedingly small. 

 The comparative silence which reigns in the pigeonry is gloomy; 

 the hushing of the birds in August is an annual surprise, a change 

 so sudden and so great that one does not l)ecome accustomed to it. 



A". The Life Cycle^ Continued. 



Though ring-doves begin to breed at a vcn- eai"ly age, even at four 

 months, and thereafter continue to pass through the regular succes- 

 sion of brood cycles and annual cycles. Professor Whitman has found 

 that they do not reach their maximum breeding powers until the age 

 of about three years. After that age, the breeding powers remain 

 at the maximum for some years. 



