MARKETING EGGS 491 



Blood Rings. — Eggs in which the embryo has developed to a 

 sufficient extent that it is quickly recognized when held before 

 the candle. It has been found that it requires between twenty- 

 four and thirty-six hours of incubation under a sitting hen to 

 produce this condition. 



Rots. — Eggs which are absolutely unfit for food. The differ- 

 ent classes of rots may be defined as follows: 



(a) Black rots. This is the easiest class of rots to recognize 

 and, consequently, the best known. When the egg is held 

 before the candle the contents have a blackish appearance, 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 that case the foreign growth has not con- 

 taminated 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 appear- 

 ances. It is probable that spot rots are caused as much by 

 mold as by bacteria, but for practical purposes the distinction 

 is unnecessary. 



To all intents and purposes, the spot rot, as explained above, 

 is practically the same as the brown and black spots described 

 under the general head of "spots." The spot rot is also placed 

 under the general head of rots simply because some candlers 

 will call it a spot, while others designate it as spot rot. Pink 

 and blood rots are names which are applied to a certain class 

 of rotten eggs, the pink rot deriving its name from the peculiar 

 pinkish color of the contents when held before the candle. The 

 same thing is true of the blood rot, which is bloody or red in 

 appearance. 



The causes for changes taking place in market eggs have 

 been classified as follows; 



