226 SWALE VINCENT 



tissue whicji must have occurred when the thyroid was extirpated in dogs 

 and cats. 



Wagner and others confirmed SchifFs observations, and it has been 

 stated that the first named author found an increased response in the 

 nerves to galvanic currents after removal of the thyroid (and para- 

 thyroids) in cats. 



Horsley was the first to operate on monkeys. He states that a week 

 after the operation fibrillary twitchings of the muscles were noted, and 

 that these ceased on voluntary movement. The animal then became 

 "cretinoid." There was a "myxedematous" condition of the subcutaneous 

 tissues. The tremors were relieved by keeping the animal warm. Ac- 

 cording to Horsley there were swellings of the skin of the face and abdo- 

 men, due to the infiltration of the tissues by mucin. The salivary glands 

 became enormously hypertrophied and the parotid gland produced large 

 quantities of mucin. 



We are not concerned in this place with the nervous symptoms de- 

 scribed by Horsley, but it may be observed in passing that so far as I am 

 aware no subsequent observer has been able to obtain these "myxedema- 

 tous" symptoms in monkeys or in other animals. Horsley gives no detailed 

 protocols of his experiments. 



Removal of the thyroid from different animals was carried out by a 

 number of observers during several succeeding years. The majority of 

 these confirmed the general views of Schiff as to the effects of total 

 extirpations of the thyroid. It must be remembered that at this period 

 the possibility of a separate functional importance of the parathyroids was 

 not suspected, so that while in dogs, cats and monkeys thyroids and 

 parathyroids were always removed together, in the herbivora the two 

 external parathyroids were left behind in what was called "total thyroid- 

 ectomy." For, although the external parathyroids were discovered by 

 Sandstrom in 1880 and by Baber in 1882, it was not until Grley (a) re- 

 discovered them and demonstrated their functional importance in rabbits 

 that experimenters gave them due consideration. This was in 1891. 



Following Horsley's work 'we have to record communcations by Welch, 

 Albertoni and Tizzoni, Fuhr (a) (&), Herzen, Rogowitsch and others. 

 These all supported the view of Schiff as to the effects of total extirpations 

 of the thyroid. But Philipeaux, Munk, Drobnick and some others were 

 inclined to deny the supreme importance of the thyroid in the animal econ- 

 omy and attributed the untoward symptoms recorded by other workers to 

 injury to nerves, reflex action, and similar causes. MumVs observations 

 are specially interesting in view of the results obtained by some more 

 recent observers (vide infra). He came to the conclusion that the chronic 

 disturbance of nutrition in thyroidless animals is nothing more than 

 "Gefangenschaftkachexie" which may often be observed in unoperated 

 animals. He states that out of four monkeys operated on in England one 



