404 POULTRY CTTLTTJRE 



White shelled eggs possess a higher percentage of fertility, 

 and of the fertile eggs there will be a higher percentage of 

 white eggs hatched than of brown shelled eggs. 



Brown eggs have a thicker shell and will require greater 

 pressure to crush than white eggs. 



Strength of Egg Shells. — ^Mr. Herrasti of South Africa tested 

 the longitudinal strength of egg shells. Nature has made 

 wonderful provision to protect against the breakage of an egg 

 by the use of the arch. In these tests brown eggs proved 

 stronger than white-shelled eggs. As an average the brown 

 eggs broke under a pressure of 155 pounds and the white 

 shelled eggs broke under a pressure of 112.5 pounds. The 

 thickness of these shells varied from 0.013 to 0.014 in. The 

 thickness of the shell will vary with many factors, but if the hen 

 is normally functionating and plenty of shell material is pro- 

 vided, but few thin-shelled eggs should be produced. It is 

 safer to keep these for home consumption than to take 

 chances on breakage in transporting. 



If a common market basket is used to ship eggs, line the 

 sides, end, and bottom with excelsior, wrap around each egg 

 paper, cotton, or excelsior until the mass is about 3 or 4 inches 

 in diameter. Pack these tightly in the basket, covering with 

 excelsior and cloth; the cloth can usually be forced between 

 the rim and the basket, using an old case knife to force it in. 

 The basket should be labeled, in large letters, "EGGS FOR 

 HATCHING"— "HANDLE WITH CARE." 



Eggs for hatching shipped either by parcel post or express 

 may be subjected to rough handling. Therefore the delicate 

 mechanism of the egg may suffer serious injury as a result of 

 concussion. Even the delicate retaining membranes may be 

 ruptured without breaking the shell. Therefore the explana- 

 tion of why eggs shipped by parcel post or express for sitting 

 purposes do not hatch so well is injury due to concussion. 



Many commercial men estimate that 65 per cent, of the 

 eggs set is an average hatch. 



In packing eggs for hatching it is necessary to have a material 

 that will be "springy" so that the concussion will be taken up 

 and the eggs not jarred so as to seriously injure them. The 

 best wrapping materials are felt, excelsior, or soft paper. 



