n88 PHYSIOLOGY 



toxic substances which would normally undergo destruction in the thyroid 

 gland. This theory is put out of court by the results of administration of 

 thyroid gland to patients with myxoedema or to animals deprived of their 

 thyroids. SchifE first showed that the effects of extirpation of the thyroid 

 might be prevented if, at the same time, the thyroid from another animal 

 were transplanted into the subcutaneous tissue to take the place of the one 

 removed. On removing the transplanted thyroid, the typical symptoms 

 of thyroid destruction at once ensued. It was later found that similar 

 good results could be obtained by subcutaneous injection of the expressed 

 juice of the thyroid, and later that even this was not necessary, and that it 

 A B C 



FIG. 547. A, a cretin, 23 months old. B, the same child, 34 months old, after ad- 

 ministration of sheep's thyroids for 1 1 months, c, a cretin, untreated, 15 years 

 old. (W. OSLER.) 



was sufficient to administer the thyroid gland, either fresh, dried, or partially 

 cooked, by the mouth. The administration of the thyroid gland in this way 

 is indeed one 'of the therapeutic triumphs of the last twenty years. An 

 ugly and idiotic cretin can be converted in this way into a child of ordinary 

 intelligence with normal powers of growth (Fig. 547). Given to myxcedemic 

 patients, the thyroid gland reduces the swelling of the subcutaneous tissues, 

 causes a new growth of hair, and restores the patient to his or her former 

 state of mental health. Nor is the thyroid gland without influence on the 

 healthy individual. If given in large doses either to man or animals, it quickens 

 the pulse, even causing violent palpitation, and increases the metabolic 

 activities of the body, so that the appetite is increased, the nitrogenous output 

 rises above the intake, and the subcutaneous fat is diminished or disappears. 

 It is possible that a moderate degree of thyroid inadequacy is not infrequent 

 and that the beneficial effects on general health, in removing excessive 



