EXOPHTHALMIC GOITER 493 



It has been suggested that the thyroid produces an enzyme 

 which destroys mucin, but that such is the case has never been 

 demonstrated. Levin 1 states that mucin is toxic for thyroid- 

 ectomized rabbits, but this is not substantiated by Nefedieff. 2 



That the thyroid is connected with general growth is shown 

 not only by the thyroid abnormalities present in cretinism, but 

 also by the frequent observation of thyroid defects in conditions 

 of delayed growth and development of less extreme degree 

 (infantilism), and the favorable effects of thyroid feeding in 

 many such cases. Also in certain types of short-limbed dwarfs 

 (chondrodystrophia fatalis) some thyroid anomaly may have an 

 etiologic bearing, for in such a case, in which the thyroid was 

 histologically greatly altered and quite free from colloid, I could 

 find no trace of iodin. 3 On the other hand, the thyroid of a 

 giant which I have analyzed contained 62.9 mg. of iodin, or 

 six times the amount present in normal glands. 4 



EXOPHTHALMIC GOITER 



It has by no means been conclusively determined that 

 exophthalmic goiter is due to an intoxication with excessive 

 amounts of thyroid secretion, either normal or abnormal, but 

 there is abundant evidence in favor of this view. Most 

 important is the similarity of exophthalmic goiter to the effects 

 of " hyperthyroidism " or " thyroidismus," produced either 

 experimentally or through overuse of thyroid extract for thera- 

 peutic purposes. In thyroidismus there are observed a rapid, 

 weak pulse ; greatly increased metabolism, especially of proteids ; 5 

 increased secretion, especially of perspiration ; marked nervous- 

 ness and irritability, often with mental confusion and delusions ; 

 gastro-intestinal disturbances, especially diarrhea ; sweating, 

 flushing, tremors, palpitation of the heart, loss of weight, 

 and slightly increased temperature are also often observed, 

 and not rarely typical exophthalmos may appear. These 

 manifestations, which are common to both thyroidism and to 

 exophthalmic goiter, are quite the opposite of the characteristic 

 changes of myxedema, with its general lowering of all metabolic 

 and nervous processes. Furthermore, the histological changes 



1 Med. Record, 1900 (57), 184. 



2 Vratch, 1901 (22), Oct. 27. 



3 Reported by Hektoen, Amer. Jour. Med. Sci., 1903 (125), 751. 



4 Reported by Bassoe, Trans. Chicago Path. Soc., 1903 (5), 231. 



5 Metabolism in exophthalmic goiter, see : F. M tiller, Deut. Arch. klin. Med., 

 1893 (51), 401 ; Scholz, Cent. f. inn. Med., 1895 (16), 1041; Magnus-Levy, 

 Berl. klin. Woch., 1895 (32), 650 ; Schondorff, Pfluger's Arch., 1897 (67), 39o ; 

 Voit, Zeit. f. Biol., 1897 (35), 116 ; Clemens, Zeit. klin. Med., 1906, Bd. 59. 



