i INTERNAL PEOTECTIVE SECRETIONS 19 



affinity to the human race might a priori be expected to show 

 a greater likeness in pathological phenomena), Horsley (1885-86) 

 reproduced and described the psychical decadence, the alterations 

 in general nutrition, the special oedenias that were described for 

 man by Reverdin, and which constituted the syndrome of operative 

 myxoedema. Tetany was occasionally observed in apes as in man, 

 and rapidly produced the death of the animal. 



Fatal effects with phenomena similar to those in dogs were 

 observed on cats (Schiff, Vassale, and Sacchi) and foxes (Sanquirico 

 and Orecchia). In some of the herbivora, on the contrary, especially 

 the rabbit, on which many experiments have been made, no 

 particular effects were observed (Schiff, Colzi, Tizzoni and Fileti, 

 Sanquirico and Orecchia, etc.) Later on we shall examine the 

 reason for these negative results, as also for the rare survival of 

 dethyroidised dogs, as noted by Albertoni and Tizzoni, H. Munk, 

 and others. Thyroidectomy in birds yielded varying results to 

 Moussu, negative results to Allara and Ewald. In reptiles and 

 amphibia, on the contrary, the physiological importance of the 

 thyroid apparatus was evident. The salamander usually died 

 after a week (Grley, Phisalix, Nicolas). Lizards and snakes 

 perished in 3-4 weeks (Cristiani). 



VII. After this description of the phenomena, the first question 

 to determine is whether the complex pathological effects observed 

 after ablation of the thyroid bodies are really the direct con- 

 sequence of loss of function in the glandular organ, or the indirect 

 effects of the operation performed on man and other animals. We 

 will shortly review the principal opinions in regard to this 

 subject. 



Prior to the observations of the cousins Reverdin and of 

 Kocher on man, which were confirmed by Schiff for other animals, 

 there was no really scientific theory of the specific function of the 

 thyroid body. The current hypotheses were more or less gratuitous, 

 or founded upon superficial observations. Among many such 

 (which need not be recorded) was that formulated by Schreger 

 (1791), which had a certain objective foundation. In view of the 

 situation of the gland between the heart and brain, of the large 

 arterial vessels with which it is provided, and of their origin in 

 the arteries that carry the blood to the brain, he opined that the 

 thyroid functioned as an organ for regulating the circulation in 

 the upper part of the body, particularly in the brain : Haec 

 glandula sanguinis immodicos appulsus a cerelro aderceat et 

 moderetur. Rush (1806) supported this hypothesis, and explained 

 the greater development of the thyroid in women by their greater 

 predisposition to emotion, which is associated with cardiac ex- 

 citement. The same doctrine was taken up more vigorously 

 by Liebermeister (1864), who attempted to bring out the great 

 importance of the regulatory mechanism represented by the 



