Poultry Keeping 



321 



How the 

 chick gels 

 out of its 

 shell 



the eighth day. About 

 two weeks are necessary 

 for the hard beak and 

 claws to develop. At 

 the end of three weeks 

 the now fully formed 

 chick begins to peck 

 with its hard beak 

 against the inside of 

 the shell, which finally 

 gives way. Thus a 

 ring is broken about a 

 third of the way around 

 the shell, when the 

 chick, by pushing with 

 its feet against the small 

 end and with its head 

 against the large end, 

 bursts the shell all the way round and is free. 



Some of the changes during the three weeks of incuba- Testing 

 tion can be seen through the shell by using an egg tester eggs 

 (Fig. 264 and Exp. 4). The tester may be simply a 

 piece of cardboard with a hole in it, opposite which 

 the egg may be held while looking through it toward 

 a lamp. The process is sometimes called " candling." 

 Eggs in an incubator are usually tested on the seventh 

 day, for then the embryo in the fertile eggs has developed 

 sufficiently to be easily seen. If an egg is infertile, it 

 will be clear like a fresh egg. Such eggs are often taken 

 out and used for food, though it is recommended that 

 they be used as feed for young chicks. (Exp. 5.) 



FIG. 264. An egg tester. The cover for 

 the lamp is of corrugated paper such as 

 packing cartons are made of. At the 

 bottom of the cover, to the right, are two 

 holes to permit the entrance of air. 



