284 



RAYMOND PEARL 



on that account, incarcerated. The symptoms, however, quickly 

 subsided. She was released on May 9 and laid an egg the same 

 day. 



Figure 12. Record of bird No. 401. 



The record of bird No. 408 almost parallels this, the chief 

 difference being in respect of the time at which broodiness 

 appeared. In the case of No. 408 it was on May 23, and was 

 clean-cut and definite. The manifestations, however, quickly 

 disappeared. On the 27th the bird was released, and laid an 

 egg the same day. 



Figure 13. Record of bird No. 408. 



DISCUSSION 



In this paper I have tried to bring together some of the facts 

 regarding broodiness in fowls which appear clearly when one 

 collects extensive and accurate statistics on the matter. The 

 essential purpose of this paper is to define the problems which 

 need further physiological analysis rather than to solve them. 

 The data presented in this paper are facts which any theory of 

 the physiological basis of brooding behavior must take into 

 account. 



