SECRETION. 



405 



testicles, showing a relation between the thyroid function and the 

 genital functions. In exophthalmic goiter, we have in a majority of 

 cases an excessive secretion of colloid by the thyroid. 



All of these various effects of thyroidectomy can be temporarily 

 prevented by a graft of thyroid; they may also be caused to disap- 

 pear either by injection of thyroid juice into a vein or under the 

 skin. The same results may be attained by raw thyroid or thyroid 

 juice by the mouth. If a graft can be made to "take," the effects 



Fig. 1466. A Case of Myxcedcma in a Girl of About Ten Years 



Of Age. (JEANDELIZE.) 



are permanent. Removal of a permanent graft will be followed by 

 all the symptoms of thyroidectomy. 



The phenomena attending extirpation are due to the absence 

 of a secretion which is formed within the thyroid, passing from it into 

 the blood. This secretion is necessary for certain of the meta- 

 bolic processes of the animal economy, especially for those connected 

 with the nutrition of the central nervous system and connective 

 tissues. Extracts of thyroid gland produce distinct pathological 

 effects in the normal subject. An injection into a vein of the decoc- 

 tion of the gland lowers the blood-pressure and increases the caliber 



