A GUIDE FOR KEEPERS OF POULTRY 135 
or oil, with a small quantity of coloring matter, albumen 
and mineral matter. The white of an egg is of different 
degrees of density. If an egg be boiled hard and dis- 
sected with care the layers of the different degrees of 
density may be peeled off one by one. The yolk is sus- 
pended in the center of the white by a sort of a cord of 
albumen much denser than any other part of it. This 
cord is known as the chalaza, and is attached to each 
side of the yolk, extending on one side to the air-space 
and on the other to the point of the egg. To keep the 
yolk globular it it surrounded by a very thin membrane, 
known as the vitelline membrane. The yolk is also made 
up of several layers surrounding a small white spot from 
which extends a canal to a spot on the outer circum- 
ference of the yolk known as the germinal vesicle. This 
spot, on the yolks of all eggs, is mistakenly thought by 
many people to be an indication that the egg has been 
fertilized, but this is not the case. It is simply the spot 
where the germ of a fertile egg is attached to the yolk, 
this germ being of microscopic size. The yolk is so 
weighted that no matter what position the egg is placed 
in it immediately turns so this germinal vesicle is on the 
upper side. The chalaza, by which it is attached to either 
end of the egg, twists one way or the other to allow the 
yolk to turn, but always keeps it suspended in the center 
of the egg, at the same time acting as a spring to prevent 
the delicate germ in the fertile egg from being injured by 
any sudden jar. 
EGGS AND INCUBATION.—Prof. Dryden found 
that the loss in weight of eggs incubated by hens in a 
dry nest was 14.87 per cent in 18 days. At the Ontario 
Experiment Farm, Prof. Graham found that eggs incu- 
bated under a hen in a nest which was open lost an aver- 
