1884.] On the Function of the Thyroid Gland. 5 



II. " On the Function of the Thyroid Gland." By Professor 

 Victor Horsley, B.S.. M.B., F.R.C.S. Communicated by 

 Professor M. Foster, Sec. U.S. Received December 5, 

 1884. 



(Preliminary Communication.) 



Up till the year 1883 the function of the thyroid gland was 

 unknown, and considered to be of slight importance, at least to the 

 adult animal. 



The theories concerning its function were — 



(1.) The one propounded by Mr. Simon, "Phil. Trans.," 1844, &c, 

 viz., that the thyroid body acted as a regulator of the circulation in 

 the brain, and possibly manufactured some substance which was of 

 primary importance for the nutrition of the central nervous system. 



(2.) That it was a true gland, and secreted a mucinous albuminoid 

 into the cavities of its acini, the secretion being reabsorbed by the 

 lymphatics. 



(3.) The thyroid gland has also from time to time been compared to 

 the spleen as an heemapoietic organ. 



Although the intimate relationship of goitre to cretinism has been 

 well known for many centuries, the fact that excision of the partially 

 goitrous thyroid in comparatively healthy people was followed by 

 severe symptoms of cretinism was first announced last year by Pro- 

 fessor Kocher, of Berne, who collected 160 cases in which the opera- 

 tion had been partially or wholly performed. In the latter class of 

 his own cases he found the patients, without exception, had become 

 cretinous. 



The symptoms described by Kocher were recognised by Dr. Semon* 

 as similar to those of Myxcedema, and he advanced the theory that the 

 conditions were allied. My experiments have proved the truth of this 

 view, since I have produced the condition of myxcedema by simply 

 excising (with strict antiseptic precautions and operating so as to 

 avoid all nerve trunks) the thyroid gland in the monkey. 



Schilf in Geneva, Wagner in Vienna, and Sanquineco and Canalis 

 in Turin, have made similar experiments on dogs, but they do not 

 appear to have found the myxcedematous condition ; simply, it 

 appears, because, for one reason or another, their animals did not 

 survive the operation long enough to develop the pathological 

 changes. 



However, they show that in the dog careful ablation of the thyroid 

 gland is followed by severe nervous symptoms, which commence a 

 few hours, or days, after the operation, by fibrillar contractions and 

 * " Brit. Med. Jour.," Not. 30, 1883. 



