Increasing 
was noted on the fourth day after the 
administration of the first dose, but 
was apparently dropping back to normal 
when, owing to the exigencies of the 
management of a large poultry farm, 
it was necessary to break up these 
isolated pens. The hens were kept 
under close observation for a period 
of one month after the last dosing and 
their general health continued excep- 
tionally good, there being not one case 
of sickness or death among any of the 
subjects, and the general appearance 
of the birds being far above the average 
for this season of the year. 
A CHECK ON THE RESULTS 
“I felt sure that the marked increase 
shown in the production of these hens, 
whcse laying had been most consistent 
and whose production curve was cn the 
decline at the time of experiment, was 
due solely to a direct stimulating effect 
on the ovaries, produced by pituitary 
substance, and to no other causes. A 
100 per cent egg production is almost 
unknown in my experience, at this 
season of the year, especially with flocks 
of this size (seventeen and eighteen in 
a pen). The conditions for egg pro- 
duction were practically ideal, but the 
same conditions, and very much the 
same weather, had obtained for a month 
previous. In order to meet the natural 
query as to whether the weather or 
other conditions might not have influ- 
enced the production of the experi- 
mental fowl, the daily egg records of 
two large laying pens were studied and 
are given in Table I for comparison.’ 
Conditions in these two pens and in 
the experimental pens were very similar. 
Feeding conditions, weather, and the 
nature of the soil were identical, the 
only difference being in the fact that 
the experimental pens were in small iso- 
lated houses, on free range, whereas the 
large flocks were in long continuous 
Fecundity 103 
laying-houses each with a_ fenced-in 
run of three and one-half acres of land. 
“In order to test the effect, if any, 
on the hatchability of the eggs and the 
viability of the chicks, 100 eggs from 
the experimental fowl were collected 
previous to dosing—that is, from May 
14 to May 20—and were set in an incu- 
bator on May 20, the eggs being from 
two hours to six days old. On the fifth 
day after the first dose, eggs were 
again collected from the same fowl, 
100 eggs being gathered from May 26 
to May 28, and were set in an incubator 
of the same make on May 29, the eggs 
being one to three days old. The 
results of these hatches are even more 
remarkable than the increased egg 
production, as is seen from Table II.4 
Prairie State Sand Tray Incubators of 
the same size were used. Conditions 
of temperature were closely regulated 
by thermostats. In both experiments 
the temperature ranged from 102- 
103.5° F., as required to give the best 
conditions for hatching. The chicks 
are being kept under observation to 
note sex and any peculiarities of growth. 
TEST ON LARGER SCALE 
“Feeling it desirable to have a further 
experiment to more fully prove the 
effect of this substance, I determined to 
dose all the hens in one of the large 
laying-houses. The house so chosen 
contained 655 one-year-old Single Comb 
White Leghorn hens (no males), and 
the dose administered to them was 45 
grams of the powder per day. Owing 
to the large scale on which the experi- 
ment was being conducted, it was only 
possible to obtain sufficient material 
for four daily doses. It was unfortun- 
ate that the dosing could not be con- 
tinued over a longer period, but the 
results obtained from these few doses 
were so marked and striking as to leave 
no doubt as to the stimulating effect of 
3 For the corresponding periods, the laying record of a flock of 657 hens was as follows: 
May 7 to May 14, inclusive, 45 per cent possible. 
May 15 to May 23, inclusive, 45 per cent possible. 
May 24 to May 30, inclusive, 44 per cent possible. 
May 31 to June 6, inclusive, 44 per cent possible. 
4 Of the 100 eggs set before dosing, 6 were infertile and 8 showed dead germs; 15 chicks died 
in shell (7 pipped); 71 hatched. 
Of the 100 eggs collected after dosing, 0 were infertile, 0 showed dead germs, 4 died in shell 
(all pipped), 96 hatched. 
