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RAYMOND PEARL 



relations were shown for the June period of broodiness which 

 began June 7. 



These illustrative cases of recurrence of brooding instinct 

 with different degrees of intensity in the same hen could be multi- 

 plied many times from our records. There can be no doubt as 

 to the essential fact that the instinct to brood varies in the 

 intensity of its manifestation at different times. 



OCCURRENCE OF THE BROODING INSTINCT OUTSIDE OF THE 

 BREEDING OR MATING SEASON 



While, as has been seen, broodiness is fundamentally a part of 

 the cyclical series of reproductive phenomena, yet under the more 

 or less artificial conditions of domestication striking changes in 

 its seasonal incidence are frequently to be observed. A hen will 



Figure 6. Showing record of bird No. 689. 



go broody at a season of the year when reproduction under normal 

 circumstances would never occur. Furthermore, it often occurs 

 at a much younger age than that at which a bird normally first 

 broods. 



An example of this sort is shown in Fig. 6, which gives the 

 laying record of bird No. 689, from November 1 to July 1. 



Here it will be noticed that the bird first became broody on 

 December 25. She did not lay again until March 4 and then 

 again became broody on March 27. It should be said in connection 

 with this record that bird No. 689 was a pullet hatched in the 

 preceding April and was, therefore, at the time when she first 

 went broody roughly eight months old. That this is extremely 

 early for broodiness to occur is shown from general statistics as 

 to the monthly incidence of the first broodiness shown by the 

 individual. During the year for which statistics on this point 



