Incubation. — Part II 



1397 



If the operator prefers to do the testing at night, a common tester and 

 a house lamp are sufficient for the purpose. On bright, sunny days 



Fig. 32. — Interior view of 

 testing room: i, Curtain 

 rolled; 2, shelf and tray 

 for untested eggs; j, shelf 

 and tray for infertile and 

 dead germ eggs 



Fig. 31. — Movable testing room: i, Curtain; 

 2, shelf 



testing may be done accurately without a 

 testing room by using a frame that fits tightly 

 against a window facing the sun. This frame 

 should be 

 covered 



with heavy 



black clot'' 

 or paper, in which is cut a round O' 

 oval opening about the size of an 

 egg. This arrangement is illustrated ^ 

 in Fig. 34. >0 



During winter weather it is 

 advisable to cover the eggs while 

 testing. This is not necessary in 

 a warm room unless the eggs axor^^^. 

 out of the incubator for some time. 

 In case the first test is made on 

 the seventh day of incubation, the 

 live germ, if strong, will show ^_ 

 distinctly the blood vessels branch- Fig. 33. — Side view of testing room cut 



ing in various directions. The away, showing: j Tester; 2 lamp; 3, egg 



tray; 4, tray j or tnjertile and dead germ eggs 

 germ should be centrally located 



in this network of blood vessels and is usually found near the air cell, 



provided the egg is held with the large end up. A live embryo is easily 



