INTERRELATION OF THE EXDOCRIX ORGANS 927 



(1909) in the dog, and Halpenny later noted a somewhat doubtful in- 

 stance occurring in a rabbit. That the parathyroids undergo hypertrophy 

 under such circumstances has been confirmed by several subsequent in- 

 vestigators. Most physiologists, however, have failed to see in this satis- 

 factory evidence that the parathyroids assume any thyroid function, al- 

 though this view was vigorously maintained by Vincent for several years. 

 More recently, Vincent and Arnason (1920) have expressed doubt of the 

 validity of Vincent's former position. The consensus of opinion at the 

 present time is that the thyroid and parathyroid glands are independent 

 in function. Whether either influences the activity of the other is un- 

 known. 



Hypophysis 



Relation between Hypophysis and Thyroid. Hallion and Alquier 

 (1908) fed to 5 rabbits for a prolonged period extracts of the whole hy- 

 pophysis of cattle. At autopsy the thyroid glands were found to have less 

 than the normal amount of colloid and the cells were somewhat more 

 columnar than normal, i. e., the glands approached the hyperplastic type. 

 Renon and Delille (1908) obtained similar results from intraperitoneal 

 injections of hypophyseal extracts. They found that posterior lobe ex- 

 tracts had much the same effect as whole gland extracts. Lucien and Pari- 

 sot (1909) repeated the experiments of Renon and Delille but obtained 

 somewhat different results. The thyroids in their animals were from 

 10 to 40 per cent heavier than those of the controls and had an increased 

 amount of colloid, an appearance "hardly indicating increased activity 

 but rather resembling a simple goiter." Sandri (1909) obtained negative 

 results in guinea-pigs both from feeding and from injecting hypoph- 

 yseal extracts. The writer (1911) obtained similar negative results 

 in case of 19 young guinea-pigs. More recently Pardi (1916) has con- 

 firmed the results of earlier observers to the effect that hypophyseal ex- 

 tracts in rabbits cause an augmentation of the colloid in the hypophysis. 

 Hofstatter (1919) treated 70 rabbits by intramuscular injections of 

 "pituitin," 1 c.c. every two days, from 20 to 80 days. He noted a decrease 

 in the colloid of the thyroid gland. The use of this extract is not equiva- 

 lent, however, to that of the whole gland. 



Several authors have studied the effect of extirpation of the hypoph- 

 ysis upon the thyroid. Smith (1916) and Allen (1916) independently 

 discovered that hypophysectomy in tadpoles results in marked diminution 

 in the size of the thyroid gland. Gushing (1912) reported exactly the op- 

 posite result in case of 6 dogs, whereas Bell in this animal obtained nega- 

 tive results. Houssay (1916) reported that in the dog extirpation of the 

 hypophysis resulted in an excessive accumulation of colloid and sometimes 

 degeneration of the cells. 



