1328 PHYSIOLOGY 



these results in man and animals to the circulation in the blood of toxic 

 substances which would normally undergo destruction in the thyroid 

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

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

 of their thyroids. SchifT 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. 



B 



C 



FIG. 545. A, a cretin, 23 months old. B, the same child, 34 months old, after 

 administration of sheep's thyroids for 11 months, c, a cretin, untreated, 

 15 years old. (W. OSLER.) 



It was later found that similar good results could be obtained by sub- 

 cutaneous injection of the expressed juice of the thyroid, and later 

 that even this was not necessary, and that it 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. 545). Given 

 to myxredemic 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 m 



