162 



HABITS OF BIRDS. 



It breaks and escapes from the shell usually on the 

 twenty-first day, but sometimes as early as the 

 eighteenth, and at other times not till the twenty- 

 seventh. 



An Egg as it appears twenty days after incubation. The vesicle and 

 amnion are removed, to show the position of the perfect Chick. 



The exit of the chick from the shell appears to us 

 to be one of the most interesting processes of ani- 

 mated nature ever investigated by naturalists. We 

 are indebted to Reaumur for a most minutely ac- 

 curate account of this process * ; and recently Mr. 

 Yarrel has given a brief detail of his own obser- 

 vations upon several species of birds. It is the 

 popular opinion, that the mother-bird breaks the shell 

 of the egg to free the chick from imprisonment, an 

 opinion which must have originated from the circum- 



* Oiseaux Domestiques, Mem. vi. 



