EGGS AND INCUBATION. 



1009 



Process of Incubation. 



Th$ white of the eggjs the principal food 

 ,*f the growing chick in the shell. It is a 

 bad conductor of heat, and often prevents 

 fatal results to the germ from sudden .changes 

 in temperature. It also preserves the del- 

 icate egg-germ from concussions. There are 

 two rather thick cords of albumen fastened 

 to the under side of the egg to balance \\, 

 thus keeping the chick always in the upper 

 part of the egg, where it can best receive 

 warmth from the hen. The yolk is absorbed 

 or drawn into the stomach through' the na- 

 vicular cord during the last twenty-four hours 

 before the chick is hatched; and this is its 

 food for a day after leaving the shell. Dur- 

 ing incubation the small round spot in the 

 yolk (that being the life-germ) becomes 

 gradually larger, absorbing the white, and, 

 thus making room for itself. On about the 

 nineteenth day the chick's beak breaks -the 

 air bubble at the end of the egg, and com- 

 mences to breathe by its lungs. On the 

 horn on the tip of the bill fractures the shell, and its 



consummated 



Fig. 1357.— Oviduct, or Egg 



twenty-first day the 

 egg life is 



Fig. 1358.— Hen's Nest (or Sitting Hen. 



Natural Incubation. 



, The time to hatch de- 

 pends on the breed and 

 also upon the purpose in 

 view. Broilers bring fancy 

 prices when very early. 

 The smaller breeds, should 

 b,e set later than those 

 which, are larger and 

 hover betteri Some peo- 

 ple hatch chicks in the 

 fall for winter and sprirfg 

 use. Early, common sit- 

 ters should not have over 

 seven or eight eggs. 



