HATCHING OF THE CHICK. 423 



This incubation normally lasts twenty-one days, but it is not 

 at all unusual for it to be prolonged to twenty-five days. The 

 writer has had fowls hatch off even at thirty days, when the 

 eggs given the hen had been laid some time previously. This 

 is especially noticeable in Indian game. It seems that the 

 longer the egg has been laid the longer the period of incu- 

 bation, within certain limits, 



