56 PROGRESSIVE POULTRY CULTURE 



(blood-ring) there has befcn a hemorrhage and death in 

 the shell. The expired embryo may then appear as a 

 dark spot close against the inner shell or floating in the 

 white of the egg. If the contents of the egg have a 

 cloudy appearance and no life movement the germ has 

 started and died. Any eggs that fail to show motion or 

 life within should be opened and examined to determine 

 what has taken place. 



If the air-cell is much enlarged there has been too 

 great evaporation of the liquid contents of the egg and 

 the amnion probably lacks somewhat of the limpid al- 

 bumen which should surround and protect the embryo. 



"Eggs which appear clear, like fresh eggs, before the 

 tester are infertile and will not develop embryos. 



At the close of the sixth day of incubating, the large 

 ends of the eggs are carefully looked at before the tester 

 to see if the blood-vesels of the blastoderm have suc- 

 ceeded in passing across under the air-cell. If the air- 

 cell has increased much in size, this passage may be 

 hindered. The distance across is increased and the di- 

 rect evaporation tends to leave the albumen between 

 the yolk and the air-cell thicker than it should be. Fur- 

 ther the net-work of veins is liable to halt in its advance 

 under the air-cell, turn at its edge and fold back upon 

 itself instead of continuing to surround the yolk as it 

 should. 



After seven full days have elapsed the veins should 

 show beyond the air-cell and correspondingly on the 

 opposite side of the yolk at the small end of the egg. 

 The embryo, at this stage, should appear very active in 

 its movements, diving about within its watery sac, now 

 disappearing from sight for a moment, deep down in 

 the amnion, then reappearing, plunging this way and 

 that and seemingly well satisfied with the conditions of 

 life within an egg-shell. 



At this stage of incubation, even dark shelled eggs 

 may be satisfactorily examined before a good egg-tester. 



If the eggs from the incubator appear to be less for- 

 ward in development than those from under the sitting 

 hens, it will be well to open several of each lot and ex- 



