PARATHYROID GLANDS 3 



This condition has several times followed a too 

 extensive removal of the thyroid in man, and may 

 also occur in myxoedema. Another symptom 

 present frequently in monkeys is narrowing of the 

 palpebral fissure, so-called enophthalmos ; we shall 

 see that administration of thyroid extract may 

 cause exophthalmos. True myxcedema is not often 

 seen in the experimental animals. It has been 

 induced in mild degree in monkeys by Horsley, 

 Edmunds, and others, but not with any constancy, 

 and in other animals it is not seen at all. 



It is not usually possible to save the lives of dogs 

 or monkeys, whose thyroids have been removed, 

 by feeding on sheep's thyroid, although a good deal 

 of relief may be obtained for the symptoms in this 

 way. Grafting a piece of the gland under the skin 

 is successful for a while, but eventually it is absorbed. 



The effects of removal of, or insufficient secretion 

 by, the thyroid gland in man are myxcedema, and 

 occasionally tetany. 



In 408 cases in Kocher's clinic at Berne complete 

 extirpation of the thyroid was followed by myxoedema 

 in 69 cases, and a similar operation in 78 cases in 

 Billroth's clinic was followed by tetany in 13 cases, 

 of which 6 proved fatal. Feeding with sheep's 

 thyroid is wonderfully successful in myxcedema, but 

 is not usually effectual in tetany. 



Partial removals of the thyroid in dogs produce 

 symptoms of correspondingly lessened severity 

 Halstead found that in one case one-eighteenth of 

 the gland sufficed to ward off symptoms of 

 athyroidism, but the amount which could safely be 



