SECRETION OF THE DUCTLESS GLANDS. 867 



as a result of unintentional removal of the parathyroids during 

 the course of a surgical operation on the thyroid bodies. Many 

 suggestions have been made in regard to the nature of the specific 

 functions discharged by the parathyroid bodies, but no one view 

 has met general acceptance. The most important of these theories, 

 at present, are the following: 1. The parathyroids are concerned 

 in some special way with the calcium metabolism in the body. 

 This view is based upon the effect of the administration of calcium 

 salts in mitigating the tetany that results from parathyroid- 

 ectomy, as stated above. In accordance with this theory it is 

 said that removal of the parathyroids is followed by an increased 

 elimination of calcium in the urine and feces and a decrease in the 

 calcium content of the blood. 2. The parathyroids are concerned 

 in the maintenance of the acid-base equilibrium of the body. 

 After parathyroidectomy there is an increase in the alkaU reserve 

 of the blood, giving a condition that may be designated as al- 

 kalosis.* 3. Antitoxic theory. Paton and his co-workers j state 

 that removal of the parathyroids is followed by an increase in the 

 guanidin compounds in the blood and urine, and that a similar 

 increase is observed in human beings exhibiting tetanj^ due pre- 

 sumably to parathyroid deficiency. Moreover, injection of guan- 

 idin compounds into animals gives symptoms similar to those 

 caused by parathyroidectomy. On the basis of such facts this 

 theory assumes that the function of the parathyroids is anti- 

 toxic, in the sense that the toxic guanidin compounds normally 

 produced in metabolism, especially in the muscles, are neutralized 

 or detoxicated in some way by the parathyroid tissue. 



An older view that the parathyroids constitute simply an 

 immature form of thyroid tissue has apparently been definitely 

 disproved, but many observers believe that there is some kind of 

 direct relationship in functional activity between the thyroids and 

 the parathyroids. Clinical cases of excessive activity of the 

 parathyroids seem not to have been reported. On the other hand, 

 cases of tetany, especially in children, have been explained as due 

 to parathyroid insufficiency, although the connection has not been 

 established definitely. Hertz | gives an interesting account of 

 what appears to have been a case of parathyroid insufficiency. 

 The patient exhibited nervousness, restlessness, depression, great 

 loss of weight, etc. The administration of dry parathyroid tissue 

 resulted in a rapid gain in weight, and finally in the restoration of 

 a normal condition of health. 



The Function of the Thyroid. — According to the opinion of 



* Wilson, Stearns, Thurlow, "Journal of Biological Chemistry," 23, 89, 

 1915. 



t Paton et al., "Quarterly Journal of Exp. Physiology," vol. 10, 1917. 

 X Hertz, "Endocrinology," 2, 145, 1918. 



