112 



Scientific Proceedings (52). 



interval being 30 and the longest 81 days. In one of the dogs 

 there was a superficial stitch infection for a few days, otherwise 

 there was in no case the slightest evidence of suppuration. 



From a restudy of the report of my experiments on extirpation 

 of the thyroid gland made in 1888, I find that, for the major part 

 of the experiments, the wounds of the dogs were left open, and 

 that after 22 days, with 3 exceptions (Nos. 105, 126 and 127) 

 there was hypertrophy, macroscopic and microscopic, of the remain- 

 ing gland in the animals whose wounds were permitted to heal 

 by granulation, whereas when the wound healed absolutely per 

 primam the hyperplasia of the remaining thyroid tissue did not 

 develop except in dogs which died from some intercurrent disease 

 such as pneumonia or distemper. 



Of the three exceptions referred to the tip only of one thyroid 

 gland was ligated in two (nos. 126 and 127) and no tissue removed 

 at the operation. 132 days later, examination of the thyroid lobe 

 revealed no hyperplasia, except perhaps to a very slight and 

 questionable degree in one of the sections of the lobe of one of 

 these dogs. The absence of hypertrophy in dogs 126 and 127 

 after 132 days may possibly have been due to the long interval 

 between the first and second operations. The hyperplasic picture 

 may, possibly, have been present and vanished, although from 

 observations of 25 years ago we know that extreme hyperplasia 

 may persist for 104 days and we have no absolute proof from 

 them that having been once established it disappears. From a 

 study of the elaborate and important work of David Marine 

 and Marine and Lenhart I am quite convinced that the return 

 to normal is to be expected. In one of Dr. Hunnicutt's dogs 

 the lobe first removed showed marked hyperplasia, whereas 

 87 days later the second lobe presented the normal histological 

 appearance. 



In the remaining case (No. 105) the veins at the upper poles of 

 both lobes were ligated and unnecessary manipulation carefully 

 avoided. On the 51st day there was no evidence of hyperplasia. 



That there is such a thing as true compensatory hyperplasia 

 is proved, I think, by my experiments in transplantation of the 

 parathyroid glandules. Thus when both thyroid lobes have been 



1 Johns Hopkins Hospital Reports, Vol. I, Table IV. 



