EXTIRPATION OF ONE KIDNEY. 171 



idea that, when one kidney is removed, in order that the 

 other shall accomplish the function of both, it must undergo 

 hypertrophy. This is stated as a fact by Paget, 1 though we 

 have failed to find any very positive observations bearing 

 upon the question. 3 It does not seem probable that the 

 secreting structure of an organ like the kidney, after it has 

 once attained its full development, can undergo physiologi- 

 cal hypertrophy, or be the seat of the development of new 

 secreting substance. Whenever the kidney is found hyper- 

 trophied in the human subject, it is due to the deposition in 

 its substance of non-secreting tissue, which generally inter- 

 feres very seriously with its function. It is more reasonable 

 to suppose that Nature has provided in the kidneys, as in 

 the lungs and other organs, more working substance than is 

 absolutely required for the elimination of the excrementitious 

 constituents of the urine ; and that even when one kidney 

 is removed, the other is competent to eliminate the amount 

 of excrementitious matter that is produced under ordinary 

 conditions of the system. 



The exceptional experiment in which the animal died 

 after extirpation of one kidney is quite interesting : Octo- 

 ber 6, 1864, we removed one kidney from a small cur-dog, 

 about nine months old, by an incision in the lumbar region. 

 The animal did not appear to suffer from the operation, and 

 the wound healed kindly. The only marked effects were 

 great irritability of disposition and an exaggerated and per- 

 verted appetite. He would attack the other dogs in the 

 laboratory without provocation, and would eat with avidity 

 faeces, putrid dog's flesh, and articles which the other ani- 

 mals would not touch, and which he did not eat before the 

 operation. On the morning of ]STovember 18th, forty-three 



1 PAGET, Lectures on Surgical Pathology, Philadelphia, 1854, p. 33. 



2 In some of the experiments of Zalesky, it is stated, in general terms, that 

 about a month after the extirpation of one kidney, the other is enlarged. It is 

 not apparent, however, that the size and weight of the two kidneys were actu- 

 ally compared. (Op. cit., p. 22.) 



