494 



POITLTRY CULTURE 



it sways readily and the air cell shifts sooner. A fresh egg out 

 of the shell has an opalescent appearance and the yolk stands 

 up. Neither of these are observed in the stale egg. A watery 

 egg may be caused by invasion by bacteria. 



The Yolk. — In a fresh egg the yolk is dimly seen before the 

 candler. The more transparent the shell the more distinctly 

 the yolk can be seen. Because of the thin condition of the 

 white in a stale egg the yolk can be more plainly seen. The 

 yolk sac weakens in a stale egg, making the yolk more and 

 more plainlj'' visible. In such an egg when broken into a dish 

 the yolk is noted to flatten out. In a stale egg the yolk has a 

 tendency to float near the shell, while in a fresh egg the yolk is 

 more nearly centrally located. Finally the yolk in very old eggs 

 may be noted to adhere to the shell. The color of the yolk 

 affects the hght passing through it. Thus a Hght-yellow yolk 

 will reflect a pink-yellow color when held before the candler, 

 and an orange yolk a red light. 



In the commercial candling room an experienced man can 

 candle a 30 dozen case in fifteen minutes. They work nine 

 hours a day handling approximately 1080 dozen eggs or about 

 3,600,000 dozen annually. 



STUDENT'S LABORATORY CHART 



Testing Eggs for Home Consumption 



(1) Number the eggs before you, very lightly, with a lead- 

 pencil. These numbers must be cleaned off later. 



(2) Estimate their size and classify as follows: 



Number of Eggs 



