INTERRELATIONS OF SECRETIONS 49 



depends on the secretory activity and stimulation of 

 others, is shown by the fact that in hypothyroidism in 

 children there is slow growth and development. Also 

 in hyperthyroidism it has been found that the most 

 severe types often are accompanied by enlargement of 

 the thymus. Retarded sexual development and quick, 

 prolonged growth before maturity is also coincident to 

 enlargement of the thymus and feeding with the ex- 

 tract (10). Then the anterior lobe of the pituitary 

 body has also an effect on growth, abnormal amounts 

 producing giantism or acromegaly, while a lessened 

 production retards growth and maturity. The feeding 

 of tadpoles with thyroid gland produces dwarfism but 

 quick maturity, which is the direct opposite of the re- 

 sults of experimental thymus feeding. 



These facts show that it is hardly possible that a sin- 

 gle gland can be at fault in metabolic disturbances, but 

 that the hypothesis must be accepted that a great many 

 internal secretions enter into the equation. Clinically 

 there has been decided improvement in certain back- 

 ward children following therapy with a single extract, 

 like pituitary or thyroid. Even then it is more rea- 

 sonable to suppose that both are more or less involved 

 in the disease [and that pluriglandular therapy is even 

 better. H.R.H.] . The reason for the improvement is 

 that the feeding with pituitary extract adds its hor- 

 monic influence to the thyroid and thereby stimulates 

 its production, and vice versa. Other influence is also 

 felt, as the rest of the glands are also stimulated to 

 secretion, for the output of adrenin is enhanced, which 

 can be seen by the rise in blood pressure, which is 

 practically always low in cretins. 



The maturing of the sexual glands also follows the 

 introduction of the above secretions. The feeding of 

 one gland having such a marked effect on the whole 

 has led us into the error of classifying endocrine dis- 

 ease as due to the disturbance of a single gland, and 



