104 The Journal of Heredity 
the pituitary substance (anterior lobe) 
on the egg production of the domestic 
fowl. 
“As will be noted in Table III,5 in 
the preliminary period, the production 
curve of these 655 hens was again, in 
this case, on the decline. In order to 
show that weather or other conditions 
did not apparently tend to increase 
production on these dates, I have again 
given (in Table III) the daily egg record 
of the flock of 431 hens. It will be 
noted in this case that the stimulating 
effect on the 655 hens lasted only about 
seven or eight days after the last dosing, 
but it will be seen that the total dose 
administered only provided, during the 
four days, the equivalent of 80 mg. of 
pituitary substance per hen and there 
is no assurance that the material was 
equally divided among the hens. It 
being impracticable to forcibly feed so 
many hens, the following method was 
employed in this case: 45 grams of 
powder were divided into three equal 
parts, each part thoroughly mixed into 
a pailful of dry mash. This mash was then 
moistened with sour skim milk and fed 
to the hens. The same quantity of this 
same moist mash had been fed to these 
hens every day for months past. It 
had been mixed in exactly the same way 
except for the addition of the pituitary 
substance, and feeding conditions and 
general care were identical during the 
experiment with conditions previous, as 
far as it is possible to make conditions of 
this kind identical. It was noted that on 
the second day after dosing, these hens 
required, and were given, a_ larger 
allowance of grain than previously, 
and the dry mash being always before 
them in open feed hoppers, it is prob- 
able that they consumed a greater 
quantity of this material than under 
normal conditions. The increased appe- 
tite was undoubtedly occasioned by 
the increase in production, the writer 
having often noted the fact that a sud- 
5 Average daily egg production of fowls: 
den increase in the appetite of a flock 
is usually a precursor of an increase in 
egg production. 
“IT am publishing this paper as a 
preliminary report. Further experi- 
ments will follow to determine: 
“1. The post period during which the stimu- 
lating effect lasts. 
“2. The smallest dose producing the desired 
results. 
“3. The general health, growth curve, and 
age at maturity of chicks from dosed parents. 
“4. A comparison of the effect of pituitary 
substance taken from growing mammals and 
from adult mammals. 
“T have other experiments under 
way at the present time. 
“At the time these two experiments 
were completed I did not know that 
work of a similar nature had been done 
by Pearl and Surface. These two 
observers administered the pituitary 
substance hypodermically to hens whose 
ovaries were in a state of complete rest 
(at the moulting season). They found 
no activation, but their experiments 
were carried out under very different 
conditions, as regards the physiological 
condition of the subjects, the method 
of administering the substance, ete. 
It seems possible to me that the nega- 
tive results they obtained as compared 
with my positive results might be 
explained by the fact that the pituitary 
substance I used was from growing 
mammals while it is probable that their 
material was from adults, as it was 
purchased from the Organotherapeutic 
Laboratory of Armour & Company. 
It is known from the work of McCord 
that positive results are obtained from 
the use of pineal body from growing 
mammals, and negative results from 
this substance taken from adults, and 
the same may be the case with pituitary 
gland. Experiments are in progress to 
test this point. 
“These experiments show that: 
“1, Feeding of pituitary gland sub- 
June 1-8: Experimental pen 45 per cent possible, laying-house 40 per cent. 
June 9-17: Experimental pen 38 per cent, laying-house 38 per cent. 
June 18-24: Experimental pen 36 per cent, laying-house 36 per cent. 
June 25—July 1: Experimental pen 51.78 per cent, laying-house 35 per cent. 
July 2-11: Experimental pen 39.14 per cent, laying-house 31 per cent. 
The first dose was 
given to the experimental pen on the afternoon of June 21 and the last dose on the afternoon of 
June 24. 
Ee a 
oT 
