Summary . — The results of the above experiments may be summar- 
ized as follows: 
Thyroid. 
Gm. thy- , 
roid fed 
daily. 
Percentage 
of iodine 
in thyroid. 
Mgm. I in 
thyroid 
fed. 
Fatal dose acetoni- 
trile in mgm. per 
gm. mouse. 
Recovered. Died. 
A. Children 
0.02 
0 
0 
0. 5 0. 6 
B . Guinea pig 
.0035 
.05 
.0017 
.8 1.0 
C. Controls 
. 3 j .35 
Thus the mice which had received the guinea pig thyroid (B) 
recovered from about one and five-tenths times the dose of aceto- 
nitrile fatal to the mice which had received the children’s thyroid 
(A). Five and seven-tenths times as much of the children’s thyroid 
as of the guinea pig’s thyroid had been fed; hence we may conclude 
that the latter was approximately eight and five-tenths times as 
active as the former. 
Series IY. 
A. THYROID OF MALTESE KID; a NO IODINE. 
Date. 
Weight 
of 
mouse. 
Remarks. 
1907. 
April 27 
12.33 
Feeding of cakes each containing 0. 05 gm. thyroid begun 
30 
12.67 1 
May 3 
12.65 
4 
12.50 
Acetonitrile, 8.75 mgms., i. e., 0. 7 mgm. per gm. mouse. Survived. 
April 27 
20. 93 
Thyroid as above. 
30 
19.82 
May 3 
20.82 
4 
21.67 
7 
21.73 
10 
22. 71 
14 
22. 95 
Acetonitrile, 20. 66 mgms., i. e., 0. 9 mgm. per gm. mouse. Died 2 hours. 
April 27 
22.53 
j Thyroid as above. 
30 
19. 51 
May 3 
21. 87 
4 
22. 42 
7 
22. 61 
10 
22. 91 
13 
22.85 
1 
Acetonitrile, 27.42 mgms., i. e., 1.2 mgms per gm. mouse. Died 4 hours. 
1 
a Unfortunately no microscopic examination was made of these glands. They weighed 17.65 gms. fresh; 
3.25 gms. dry. Thus more than 81.5 per cent consisted of water. They were apparently abnormal (gland- 
ular hyperplasia?). 
