6 
Scientific Proceedings (40). 
for a single analysis, and third, we had no sure evidence that 
iodine was being ingested in the food. 
In order to be in a position to give a more decisive answer to 
the question, we have since repeated our experiments on a much 
larger scale. We removed the thyroid glands completely from 
eighteen lambs (seven to eight months old) and twelve adult 
sheep. After the operation they were divided into two groups and 
boarded out at separate farms in the vicinity of Ithaca, N. Y. 
The lambs (group I) were fed on clover hay, oats, beets, turnips 
and small quantities of cotton seed meal; the adult sheep (group 
II) in addition to this received daily, mixed with their food, half 
a gram of sodium iodide, to ensure that iodine was being ingested. 1 
No marked symptons followed the operation either in group I 
or group II and they were killed at the end of five to six months. 
The pituitary glands were removed, desiccated, and examined for 
iodine by Hunter's method. 2 The amount of dried pituitary 
obtained from each group was sufficient for two analyses (four 
in all) and no iodine was found. 
In order to give ample time for the elimination of all circu- 
lating iodine, no sodium iodide was administered to group II for 
ten days before their slaughter. 
Our experiments therefore prove conclusively, we believe, 
that no iodine appears in the pituitary of the sheep after complete 
removal of the thyroid gland, and assuming that the iodine con- 
taining body is the physiologically active constituent of the thyroid 
gland, as it is claimed to be by Reid Hunt 3 and others, it would 
appear that the pituitary does not compensate for thyroid in- 
sufficiency. 
*In group I in addition to the eighteen lambs from which the thyroids were 
removed, one normal lamb was kept as a control. When killed along with the others, 
the amount of iodine found in the thyroid of this lamb (3.33 mg.) was three times 
•as great as the average (1.11 mg.) for the eighteen at the time of thyreodectomy, 
five to six months previously. This showed that the natural food did contain iodine 
although none had been mixed with it as in the case of group II. 
2 Hunter, Jour. Biol. Chemistry, vii, May, 1910. 
3 Reid Hunt, Public Health and Marine Hosp. Publications, Bulletin 47, Wash- 
ington. 
