WHAT THE SIZE OF AN EGG MEANS 
Current Belief that Small and Large Eggs Are Produced at the Beginning or End 
of a Hen’s Laying Period is Found to Be Wrong—Usually Appear 
When Hen is Laying Most Heavily and Steadily 
D. E. WARNER AND Ws. F. KIRKPATRICK 
Department of Poultry Husbandry, State Agricultural College, Storrs, Conn. 
and other observers that the very 
small and very large eggs which 
hens occasionally lay are the first 
or last eggs of the hen’s laying period. 
Lewis! states that “‘the extremely small 
eggs laid by hens during their laying 
period are common at the beginning 
or end of the hens’ laying period.” 
The JOURNAL OF HEREDITY? in a review 
of some recent work on Xenia in Fowls 
shows a photograph from the Bureau 
of Animal Industy, U. S. Department 
of Agriculture, and states that ‘eggs 
of any individual hen tend to become 
a litte smaller as she approaches the 
end of her laying period and the last 
one, it is generally believed, is likely 
to be a dwarf.”’ 
That this idea is wrong the writers 
have been able to demonstrate by a 
study of the abnormal eggs laid by the 
hens in the third and fourth egg laying 
contests held at the Connecticut Agri- 
cultural College, Storrs, Conn., for the 
year ending October 30, 1914, and up 
to June 1, 1915. 
The number of eggs laid by the 1,820 
hens during the 20 months’ period was 
199,137 of which 103 were small (less 
than .09 of a pound) and 89 were large 
(over .179 of a pound). The small 
and large eggs had been credited to 
the hens that laid them and the weights 
of the individual eggs also had been 
taken. The 103 small eggs were laid 
by only 85 hens, showing that only a 
small percentage of the hens laid a 
small egg during their first year of 
|: IS believed by some poultrymen 
1 Productive Poultry Husbandry, page 306. 
laying. Four hens out of the 85 laid 
two small eggs at different periods of 
their productivity. One hen, No. 900, 
laid fourteen small eggs at different 
periods and did not have a single normal 
egg to her credit when she was removed 
from the pen. This is an exceptional 
case and further studies are under way 
in order to determine the cause. 
NO REST PERIOD 
The first attack on the mass of 
figures was intended to determine 
whether a hen usually rested after lay- 
ing a small egg. It was found that only 
two eggs out of a total of 103 indicate a 
resting period*® after the production of 
a small egg. In every other case the 
small egg was found in an almost 
uninterrupted series of normal eggs. 
This seems to prove conclusively that 
small eggs may be laid at any time 
during a hen’s laying period and that 
most small eggs are laid while hens 
are at the height of production. Out 
of the 103 small eggs, 42 show no resting 
period whatever; in 34 cases the hen 
rested on the following day, in 13 there 
was a resting period of 2 days, in 4 
cases there was a pause of 3 days, 
8 cases show an average period of 6144 
days, and only 2 cases, as noted above, 
showed a real resting period. But none 
of these interruptions of the laying is 
great enough to be considered a real 
testing period; none of them is greater 
than is often found with any normal 
hen during the period of her greatest 
® JOURNAL OF HEREDITY, Vol. 6, No. 5, May, 1915. 
3 Bulletin No. 82, Connecticut Agricultural College. 
rests after becoming broody is about 19.2 days.’ 
128 
“The average length of time that a hen 
