PARATHYROID GLANDS G29 



Since the evidence thus far adduced points to- an antagonism between the 

 functions of the parathyroids and those of the chromaffin system, the occur- 

 rence of symptoms of hyperchromamnism in tetany need not surprise us. 



Kocher of Berne, however, called attention, on the contrary, to the 

 fact that marked pigmentation of the skin, and even bronzing of the skin, 

 may develop after strumectomy in man, if the symptoms of tetany are 

 prominent. 



Pancreas 



There is but little pointing to disturbances of the pancreas in associa- 

 tion with tetany. Temporary alimentary glycosuria has, however, been 

 observed in attacks of idiopathic tetany in human beings. In the experi- 

 mental tetany of dogs, too, the capacity of the organism to assimilate glu- 

 cose seems to be depressed. But Kojima (a) (1917) found that the addi- 

 tion of parathyroid substances to the daily diet of animals caused no bisto- 

 logical changes in the pancreas'; he examined the islands of Langerhans 

 carefully, but could discover no alterations in them. 



f Gonads 



The relations of menstruation, of pregnancy, and of lactation to tetany 

 are among the well established facts connected with the subject; these 

 conditions all predispose to the occurrence of tetany. Maternity tetany 

 has been as well studied, perhaps, as any form of tetany. Evidently the 

 demands made upon the parathyroid functions during maternity are often 

 greater than can be met by the glands supplying the secretion. Whether 

 or not these demands originate in changes in the gonads is a matter that 

 has not yet been determined. 



In experimental partial parathyroidectomy in animals the lessened 

 parathyroid function that results may suffice for the ordinary life of the 

 animal though not for extraordinary demands, for if pregnancy occur, 

 tetany will develop. Iselin has made the further interesting observation 

 that even the offspring of parathyroidectomized rats show a markedly in- 

 creased electrical excitability of their 1 motor nerves, and they are so sensi- 

 tive themselves to parathyroidectomy that within from four to ten hours 

 after that operation, presenting the phenomena of a violent tetany, they die. 

 It is believed that this influence of the parathyroidectomized mother on 

 her offspring is not transmitted through the germ plasm, but depends 

 rather upon a diminution of the supply of parathyroid secretion to the 

 fetus while it is within the uterus. 



Experiments of Silvestri (&) (1910) had indicated that the previous 

 extirpation of the gonads can prevent the tetany that otherwise will develop 

 in thyroparathyroidectomized animals. These findings, however, have not 

 been confirmed by subsequent investigators. Silvestri's experiments have 



