THE THYROID AND PARATHYROIDS 289 



parent appearance. It is as if the skin were saturated with a 

 semi-fluid substance. Peculiar, glistening, highly refractive 

 bodies, whose nature is not known, have been found. A 

 similar condition is reported in other organs and tissues. 



The chemical nature of the infiltration is not certainly known. 

 It is very doubtful whether it is mucin, and there are many 

 reasons for thinking that it has not the composition of ordinary 

 oedema. Cases in which a chemical examination of the skin 

 may be carried out are so rare that it will probably be many- 

 years before the matter can be satisfactorily settled. Ewald 

 thinks that there is a trophic change in the direction of degenera- 

 tion of fatty tissue or a persistence of the embryonic mucous 

 tissue. 



(c) Paihogeny. In the view of perhaps the majority of 

 physicians and pathologists who have studied the subject, 

 the pathogeny of myxcedema is very simple. Thus, Murray- 

 says : ' ' These facts clearly show that myxcedema in man is 

 entirely and solely due to disease or removal of the thyroid 

 gland and the consequent failure of the supply of its in- 

 ternal secretion." We have seen (p. 140) that in the case 

 of Addison's disease it is difficult or impossible to produce 

 artificially the symptoms of this disease by extirpation of the 

 adrenals in animals. The most striking of all the symptoms 

 namely, pigmentation of the skin does not occur in the oper- 

 ated animals. Similarly we shall see (p. 303) that in animals 

 deprived of their thyroids swelling of the skin and subcutaneous 

 tissues is, at any rate, not a common symptom, and according 

 to some observers cannot be induced at all. It must be remem- 

 bered, however, that it is scarcely possible to imitate artificially 

 the exceedingly gradual fibrosis and destruction of glandular 

 tissue which occurs in myxcedema. 



The parathyroids are intact according to the majority of 

 observations, but there is some evidence that the pituitary 

 body may be concerned. 



4. Cachexia Strumipriva 



In 1882 Reverdin described the results of goitre extirpation. 

 In the following year Kocher published his classical report 

 on eighteen cases. Later in the same year J. and A. Reverdin 

 noted the resemblance of the symptoms to those described by 

 Gull, and hence called the condition " operative myxcedema." 



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