6 BULLETIN 565, U. S. DEPARTMENT OP AGRICULTURE. 



and the other two eggs are brought forward by a dexterous move- 

 ment of hand and palm, held before the light, and graded. The 

 ability to shift two eggs in each hand makes for more rapid work 

 and may be acquired by practicing with china eggs. A good deal of 

 experience is required to shift eggs safely and quickly. 



During candling the egg should come in contact with the fingers 

 as little as possible, so that small blemishes such as mold spots will 

 not be hidden from view. It is advisable not to hold more than two 

 eggs in each hand during candling because of the added chance of 

 breaking the eggs and confusing the grades. 



Until the beginner has had some experience it will be advisable 

 for him frequently to check the decision reached by candling with 

 the appearance of the egg when broken into a saucer or other con- 

 venient receptacle. 



WHAT TO LOOK FOR IN CANDLING AN EGG. 



The relation of the shell, air space, white, and yolk to grading by 

 candling will be discussed separately before taking up the considera- 

 tion of the different kinds of eggs. After the beginner has become 

 acquainted with the different factors which influence the grading of 

 an egg, it is a comparatively simple matter for him to recognize the 

 predominating characteristics of each egg and to place the egg in its 

 proper grade. 



THE SHELL. 



It is possible to grade eggs by inspection through the shell because 

 of the partial transparency of the shell when held before a light in 

 a dark room. The egg contents can be seen much more plainly 

 through a white shell than through a brown one. The light shining 

 through a white egg, on candling, is yellow, with a slightly pinkish 

 tinge ; that from a brown egg is much pinker ; and that from a dark 

 brown egg is almost red. In each instance, the color deepens in the 

 region of the yolk. The contrast between the white and the yolk 

 is much greater in white than in brown eggs. The appearance before 

 the candle of a fresh white and a fresh brown egg is shown in 

 Plates I and II. The beginner should study eggs with white shells 

 first and postpone the study of eggs with brown shells until he has 

 had some experience. Likewise he should begin with clean eggs, for 

 the reason that dirt or stains on the shell may cast a shadow on the 

 contents and thus render accurate candling difficult. Candling of 

 eggs with mottled, warty, or uneven shells should also be deferred. 



The colored sketches of the different kinds of eggs shown in this 

 bulletin were made, with few exceptions, from eggs with white shells, 

 and were selected to show as much of the interior as possible. The 

 descriptions in most instances will apply to white eggs. These facts 



