Hatching with Incubators 149 



Circulation through the tiny sacks of the tempor- 

 ary membrane ceases, and pulmonary circulation 

 begins, the blood going into the lungs to be purified, 

 and into the heart to be pumped through the little 

 body. 



But this new supply of air will soon be exhausted. 



Mother Nature whispers in the ear of the chick. 

 Drawing back his head he strikes as hard as he can 

 on the inside of the shell. Blow after blow he 

 deals with his beak on the same spot. 



It becomes clear now why hatching eggs must be 

 smodtli and free from thick spots. If there is a 

 ridge or thick spot at this point, he strikes and 

 strikes in vain. His little beak cannot break 

 through. At last the air is exhausted; his blows 

 become weaker; his head droops, and he dies even 

 before he has really lived, a victim of careless egg 

 selection. 



If the shell is smooth and even, before long the 

 beak goes through, and Chicken Little is rewarded 

 with a long breath of fresh air. 



Having rested a moment, and refreshed himself, 

 the chick picks out a new spot near the first hole. 

 If the egg is smooth he can make one hole after 

 another, round the egg, about one-third down from 



