514 SUTHEELAKD SIMPSON 



ical knowledge. They studied serial sections of the thyroid in the cat and 

 dog, and became thoroughly acquainted with the topographical positions of 

 the four parathyroids in these animals. They then proceeded to extirpate 

 hoth internal and external "epithelial corpuscles" in nineteen animals- 

 ten cats and nine dogs. Of the cats so treated, nine succumbed within ten 

 days, most of them about the fifth day following the operation. They pre- 

 sented a typical morbid syndrome, viz., fibrillary contractions and muscu- 

 lar spasms, psychical depression, rigid and uncertain gait, anorexia, tachy- 

 cardia, rapid emaciation, fall in body temperature, and death. One of the 

 cats, operated upon on January 5, 1896, was still alive when the paper 

 was written in March of the same year, but it was greatly emaciated and in 

 a state of chronic cachexia. 



Of the nine dogs included in the research, all perished within eight 

 days, most of them on the third or fourth day after the operation. They 

 were in good condition on the day following the operation ; they began to 

 show symptoms on the second or third day, and died shortly after. Involv- 

 ing the nervous system, there were tremors, psychical depression, paresis of 

 the muscles of mastication, trismus, rigidity of the hind limbs, uncertain 

 gait, general muscular weakness, slight convulsions, and then, most fre- 

 quently, death. There were loss of appetite and vomiting, indicating dis- 

 turbances of the digestive system, palpitation and dyspnea ; the urine was 

 very scanty and sometimes showed traces of albumin. 



The symptoms, the observers concluded, which follow the removal of 

 the four parathyroid glands are analogous to those which result in the cat 

 and dog from complete thyroidectomy, that is, the simultaneous removal 

 of the thyroid and all parathyroids. They draw attention to the fact that, 

 in their experiments, the acute convulsive symptoms were not accentuated, 

 but, on the contrary, that there was evidence of diminished excitability of 

 the nerve centers, ending in a rapidly fatal paralysis. At the postmortem 

 examination was found slight congestion of the liver and kidneys and, in 

 some cases, a certain degree of anemia of the nervous system, but nothing 

 specific to point to the cause of death. Nothing in the operation, as such, 

 could account for the fatal termination. There were no complications and 

 no involvement of the thyroid itself, nor of the nervous structures in the 

 vicinity. In most of the animals the wounds healed by first intention ; in 

 the cats, indeed, there was frequently complete cicatrization. The exter- 

 nal parathyroids were enucleated with scarcely any injury whatever to the 

 thyroid, and in taking away the internal parathyroids with curved scis- 

 sors, especially in the cats and dogs, very little thyroid tissue was removed 

 along with them. No change was found in the thyroid, except that in 

 some cases colloid material was absent from the intraglandular and peri- 

 irlandnlar lymphatic spaces. With regard to the possibility of nerve lesions 

 iviving rise to the symptoms, these could not be greater, they concluded, 

 than would be produced by complete thyroidectomy. 



