358 Kojima 



both groups. Durinor the period o£ thyroid feeding there was a decrease 

 in the consumption of food in both groups. The amount of nitrogen taken 

 in is strictly parallel to the amount of food consumed (Tables IV. and V., 

 Charts 8 and 9). 



The amount of nitrogen in the urine is also parallel to the amount 

 taken in : it is decreased during thyroid feeding (Chart 10). 



The retention of nitrogen in the body is also parallel with the amount 

 of nitrogen taken in, and is decreased during the period of thyroid feeding 

 (Chart 11). 



It would appear from the general results of this series of experiments 

 that in unoperated animals the effect of parathyroid feeding upon nitrogen 

 metabolism is negligible. 



Gaseous Metabolism. 



Third Series. After Thyroidectomy and Parathyroidectomy. 

 — The animals belonging to A, B, and C groups of the first series were 

 used in these experiments, the estimation of CO2 being made twice on each 

 group before the operation. For the estimation of COg Haldane's method 

 was employed. The COg output at the outset was very nearly the same 

 in all the groups (Tables VI. to VIII., Chart 12). 



Several days after thyroidectomy had been performed on the animals 

 belonging to Group C another estimation was made. These then showed, 

 as compared with the animals of Groups A and B, marked diminution of 

 COg excretion ; this was also apparent in the same (thyroidectomised) 

 animals after several days' feeding with meat and rusks. With that diet 

 there is, however, also a diminution of the CO2 excretion in the animals 

 belonging to Groups A and B, but not so marked as with Group C. After 

 six or seven days' addition of thyroid to the diet there was in all groups a 

 still further diminution of COg excretion. On subsequently adding para- 

 thyroid to the diet instead of thyroid, and continuing this for seven days, 

 there is a small increase of COg output in all the animals. It will, how- 

 ever, appear from the next series of experiments that the augmentation 

 of COg output, which occurred after parathyroid feeding, was not due 

 directly to that, but to the cessation of the thja-oid feeding. 



Fourth Series. With Parathyroid and Thyroid Feeding. — In 

 another series of experiments (on the same groups of animals (three males 

 and three females) as were employed in the N-metabolism experiment of 

 the second series) the estimation of CO., output was made after five and 

 ten days of thyroid feeding respectively. Two males were used as a control, 

 these being fed on the same diet as the others, but without the addition 

 of either thyroid or parathyroid (Tables IX. to XL). (It may be noted 

 that the amount of COg excretion in female rats is always less than that 

 of males under the same conditions of food, etc.) 



After five days' thyroid feeding both the males and females showed a 

 marked diminution of COg output, while there is no difference after para- 



