122 POULTRY BREEDING 
some ege's are opened at each end and the contents blown 
out, afterward filling the shells with plaster of paris mixed 
into a paste with water, this will soon become hard and 
the eggs will be more resistant than boiled ones. Such 
filled eggs can afterward be used for nest eggs or for 
“dummies” to put under hens until they have settled 
down to sit steadily, when they are to be used in hatching. 
EGG-PRODUCTION WITHOUT MALES.—It has 
been quite well established by tests that hens kept sep- 
arated from male bird will produce more eggs than those 
that run with males. In one experiment 5 hens, 5 pullets 
and a cock were put in one pen and 5 hens and 5 pullets 
in another. All were of the same breed and were given 
the same care. The experiment continued from January 
until September. The mated females produced 959 eggs 
and the unmated ones 972, a difference of 23 in favor of 
the unmated ones. In another experiment practically the 
same results were secured. The theory is that unmated 
hens are not worried by the male and being more quiet 
retain more energy to be devoted to the production of 
eggs. In the Australian laying competition, continued 
year after year with 600 hens, an average ege production 
of 186 eggs per year has been secured, the hens all being 
unmated. 
EGGS, EFFECT OF THUNDER ON.—There is a 
tradition that thunder during the period of incubation 
destroys embryo chicks. This belief is as old as the first 
century of the Christian era, but is absurd on the face of 
it, as during the hatching season heavy thunder storms 
are not at all uncommon and yet we do not hear of any 
widespread damage from this source. Careful observya- 
tions have shown that thunder has no appreciable effect 
on the growth of embryo chicks. 
