MALFORMED EGGS AND THEIR CAUSES 305 
germ, which can easily be distinguished by its whitish color and 
circular shape. 
The function of the yolk is to nourish the chick for the first 
few hours after hatching and during the early stages of its growth. 
It is just as essential to the young chick as is the colostrum to the 
calf. It supplies nutrients in easily digestible form, at the same 
time exerting a laxative influence which starts the digestive 
processess. 
Composition of the Egg.—Aside from its shell, the hen’s egg 
resembles in its composition the adult’ bird. Wheeler gives the 
following analysis: The dry matter of the egg, exclusive of the 
shell, shows the following proportion of constituents, water not 
considered: 49.8 protein; 3.4 ash; 38.5 fat. 
Considering the total dry matter in the whole egg, shell in- 
cluded, we find the proportions to be: 38.5 protein; 35.6 ash; 
25.4 fat. 
A fresh-laid egg with a good sound shell, including water, 
shows the following analysis: 13.2 protein; 11.4 shell, 0.8 other 
ash; 8.9 fat; 65.7 water. 
The ash found in the egg, aside from the shell, is rich in phos- 
phate. The shell consists almost entirely of carbonate of lime. 
Malformed Eggs and their Causes.—Soft-shelled eggs are due 
either to the absence of shell-forming material in the feed or to 
disease in the lower part of the oviduct which results in an insuffi- 
cient secretion of lime salts. In rare cases, however, they may be 
caused by the fowls not eating enough of shell-forming material, 
even when an abundant supply is available. Sometimes the bird 
is too fat, and this results in an absence of muscular tonicity, the 
egg being passed down the oviduct so rapidly that the secretions 
are not supplied in sufficient amount. 
In the ordinary course of eggs down the oviduct, they should 
mature at such times that only one will be laid at a time; but in 
consequence of improper feed, usually too much of carbohydrates 
or fat, the bird deposits excessive fat, the organs contract and do 
not permit the free passage of the ovum, finally one of two things 
may result. Two ova may pass into the oviduct nearly at the 
same time, or one may be held near the upper end until another is 
formed there, when the combined force of the two will propel 
them down the oviduct, this resulting in an egg being laid with 
two yolks,—the commonly seen double-yolked egg, which is usually 
of excessive size because of the twin yolks. 
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