EFFICIENCY OF COMMERCIAL EGG CANDLING. 9 



ing skilled in the grading of eggs with stuck yolks. When they are 

 the prevailing type of bad eggs present judgment of grade should 

 be made as far as possible with the first turning of the egg before 

 the candle, because further rotation often serves to make detection 

 more difficult. The distinguishing feature to be looked for is the 

 adhering portion of the yolk. 



In the lots of eggs reported in Table 2 from 40.57 to 78.70 per cent 

 of the eggs with slightly adherent yolks were found by candling. In 

 the summer breaking stock and refrigerator eggs it was the leading 

 type of eggs miscandled (Tables 2 and 3). 



BLOOD KINGS AND LAEGE EMBRYOS. 



Fertile eggs containing blood rings occur most frequently when 

 the weather is sufficiently warm to cause development of the germ 

 spots. In the early stages when there is but a mere trace of blood 

 present, it is not always easy to find them by candling, especially if 

 they happen to be inclosed in a brown shell. In the later stages 

 when the yolk is weak, the blood ring may be covered with a fold 

 in the yolk, and thus escape detection. The blood ring is best seen 

 if the egg is turned gradually before the candle so that the yolk 

 revolves slowly, allowing the germinal spot and the surrounding 

 area which has a rosy appearance to float near the shell. When the 

 yolk is near the shell a darkened area should be looked for, and, if 

 this is present, it should be examined carefully for dark or red stpeaks 

 or a ring. A candle with a bright light is absolutely necessary if 

 small blood rings are to be found. When the blood-veined area has 

 developed to the size of a 5-cent piece or larger its detection is 

 ordinarily a simple matter. 



The ease with which serious errors in failing to find blood-ring eggs 

 may occur, was well illustrated in one house under observation where 

 careless candlers working with dimly lighted candles put 3.4 per- cent 

 o-f such eggs into seconds intended to be edible. In the summer 

 breaking stock as many blood rings as white rots were misgraded 

 (Table 3). The use of a candle with a weak light or with an open- 

 ing which is too large results in failure to detect these eggs. 



EGGS WITH BLOODY WHITES. . 



Eggs with bloody whites are caused by the rupture of the biood 

 vessels during the passage of the egg down^ the oviduct. Their 

 occurrence is comparatively rare, for out of 357.2 cases of eggs 

 studied but 23 were found. Of these 7 were found by candling and 

 the balance by breaking. These eggs are not readily seen in the 

 shell because the pinkish tint due to the presence of blood is very 

 nearly the same as that given by a brown shell or a white shell con- 

 58079°— 18— Bull. 702 2 



