PROGRESSIVE POULTRY CULTURE 59 



the shell but becomes choked with unused albumen and 

 dies by strangulation. 



Death in the shell is sometimes associated with un- 

 timely changes of the allantois. This temporary organ 

 by its net-work of blood-vessels gathers nutriment from 

 the albumen and partly takes the place of lungs, by 

 gathering oxygen from the air through the pores of the 

 shell. The blood of the allantois veins should be with- 

 drawn into the body of the chick at about the time the 

 lungs come into use. If the allantois blood circulation 

 ceases too soon, before the chick breaks the shell, the 

 lungs may not get a sufficient supply of air and suffoca- 

 tion results. This condition may be due to lack of ade- 

 quate ventilation of the eggs during the third week of 

 incubation. 



On the other hand the allantois may continue active 

 operations too long, after the lungs are in use for breath- 

 ing. Carbonic dioxid gas is inhaled wih the little air 

 obtainable and if the chick's bill does not quickly break 

 through the shell, death by asphyxiation or exhaustion 

 occurs. Excessive ventilation of the eggs during the 

 latter half of the period of incubation aggravates this 

 condition. Thick, tough shells increase the danger 

 from this disorder. 



If the shells of the eggs have not become sufficiently 

 weakened to permit of being easily pipped, and hatching 

 is prolonged beyond the twenty-first day, some chicks 

 may fail to emerge but if they did hatch would very 

 likely come out cripples. 



Before hatching th3 chick should enclose the re- 

 maining yolk within its abdomen. If there is a failure 

 to do this and to completely close the navel, it is better 

 that the chick should die in the shell rather than to 

 come forth to be disembowelled and suffer a lingering 

 death. 



THE NATURAL METHOD OF HATCHING. 



The majority of chickens are hatched by means of 

 sitting hens. Where only a few broods or even several 



