180 POULTRY PRODUCTION 



any other position or without turning. It is considered good 

 practice to tiu'n all eggs daily during the whole time they are 

 held. 



Washing Hatching Eggs. — Eggs that are stained or dirty 

 are frequently washed with the hope of increasing their 

 hatching power. As a protection against disease, hatching 

 eggs are often washed in alcohol or other disinfectant. 



Washing eggs destroys their protective coating, called the 

 cuticle or bloom, and allows more rapid evaporation. As 

 shown elsewhere, when artificial incubation is practised, 

 evaporation is likely to be abnormally rapid, and any practice 

 which increases evaporation should be looked upon with 

 suspicion. Jackson^ found in a test where 440 eggs were 

 incubated in several groups, and half of each group was 

 washed and half unwashed, that the unwashed eggs hatched 

 12.5 per cent, more vigorous chicks, than washed eggs. 



Where eggs are broken in a nest and their contents smeared 

 over other eggs in the iiest, it is very likely to prevent the 

 latter from hatching. In this case, \vashing appears to be 

 the lesser of two evils. 



In cases where it seems advisable to disinfect hatching 

 eggs, they should be dipped, instead of sponged or washed, 

 and allowed to dry without being rubbed. 



Resting Shipped Eggs. — Persons shipping eggs any distance 

 for hatching, frequently furnish instructions to the effect 

 that the eggs are to be unpacked, placed in a normal position 

 on their sides, and rested twenty-four hours before setting, 

 for the purpose of allowing the germ to resume its normal 

 position at the uppermost point of the yolk. Such resting 

 does no harm beyond increasing the holding period by so 

 long, but it remains to be proved that the eggs cannot rest 

 just as successfully in an incubator or under a hen as in 

 any other place. 



Warming Hatching Eggs. — Under natural conditions all 

 eggs but the one laid last are of necessity held for hatching 

 for a longer or shorter time. Jackson'' observed that very 

 often the oldest egg in a clutch was frequently the first to 



■ Pennsylvania Bulletin No. 120. ' Ibid. 



