THE BROODING INSTINCT IN THE DOMESTIC FOWL 275 



an egg on the same day. In this case we have periods of visible 

 manifestation of the brooding instinct lasting 15 days in one case, 

 10 days in a second case and 4 days in the third case. This 

 certainly indicates a considerable degree of variability in the 

 manifestation of the instinct. 



Figure 4. Showing the egg record of bird No. 4. 



A similar relation is shown in the case of bird No. 444, whose 

 record from November 1 to July 1 is shown in Fig. 5. 



This bird was broody at five different times during the period 

 here under consideration. On the first occasion, she was noticed 

 to be broody on January 8, having last laid on January 5. She 

 was released on January 17, but did not lay until February 13, 

 a rest period of 38 days. When she next became broody on 

 March 15, there was an interval without laying of only 13 days. 



Figure 5. Record of bird No. 444. 



The rest period of her next broodiness was still shorter. This 

 began on April 16 and lasted but 10 days, on one of which (April 

 17) the bird laid an egg. The next period of broodiness began 

 May 10. Visible signs lasted 6 days. The whole period during 

 which egg laying stopped was 12 days. Essentially similar 



