346 POULTRY BREEDING AND MANAGEMENT 



Blood Rings. Eggs in which the embryo has developed 

 to a sufficient extent so that it is quickly recognized when 

 held before the candle. 



Rots. Eggs which are absolutely unfit for food. The 

 different classes of rots may be defined as follows : 



(a) Black Rot. This is the easiest class of rots to recog- 

 nize and consequently the best known. When the egg is 

 held before the candle, the contents have a blackish appear- 

 ance, and in most cases the air cell is very prominent. The 

 formation of hydrogen-sulphid gas in the egg causes the 

 contents to blacken and gives rise to the characteristic 

 rotten-egg smell, and sometimes causes the egg to explode. 



(b) White Rot. These eggs have a characteristic sour 

 smell. The contents become watery, the yolk and white 

 mixed, and the whole egg offensive to both the sight and the 

 smell. It is also known as the ' * mixed rot. ' ' 



(c) Spot Rot. In this case the foreign growth has not 

 contaminated the entire egg, but has remained near the 

 point of entrance. Such eggs are readily picked out with 

 the candle, and when broken show lumpy particles adhering 

 to the inside of the shell. These lumps are of various colors 

 and appearances. 



White and Brown Eggs. The color of the shell in cer- 

 tain markets affects the price of the egg. Most markets in 

 the United States prefer the white egg. New York markets 

 pay a premium for white eggs. Among the best grades, 

 brown eggs sell for about 20% less than white eggs. There 

 is no difference, however, in price of cheaper grades on ac- 

 count of color. In San Francisco the brown egg is also 

 discounted. In Boston the reverse is true, the brown egg 

 being preferred. 



This does not mean that there is any difference in the 

 quality of the brown and the white egg. The difference 

 in price is, however, undoubtedly due in part to the mis- 



