532 DAVID I. MACHT 



but so did thp extracts of many other glands. It was furthermore found 

 that the fresher the extract used the more marked were its thromboplastic 

 properties. This led to a chemical examination of a considerable quantity 

 of prostatic substance and the results of the chemical work showed that 

 the thromboplastic properties of the prostate were attributable to the 

 presence in it of kephalin. Inasmuch as kephalin is a constituent of a 

 great many glands and tissues, the thromboplastic properties of prostatic 

 extracts cannot therefore be regarded as specific. 



Effect of Prostatectomy on the Behavior of Albino Rats. It is well 

 known that following the most successful operative extirpations of the 

 prostate gland, many patients are rendered temporarily, and sometimes 

 permanently, inefficient, either mentally or physically, .or both. Such 

 deplorable sequelae of prostatectomy are almost universally attributed by 

 urologists to senility, operative shock, renal insufficiency and other causes. 

 Can such an impairment in mental efficiency be attributed to the extirpa- 

 tion of the prostate gland and the consequent deprivation of an internal 

 secretion elaborated by it ? This question is still unanswered. In order 

 to clear up this problem, at least partially, the present author, in collabora- 

 tion with Mr. William Bloom, has undertaken the following experimental 

 investigation (1920) : 



Albino rats were trained in the circular maze devised by Prof. John 

 Watson, and their neuromuscular, as well as mental, efficiency was noted. 

 Such rats can generally find their way through the intricate labyrinth of 

 the maze to its center, by the shortest route and in the shortest period of 

 time, after being trained from ten to twenty days. In order to study the 

 effect of the prostate gland on behavior, a series of rats were operated 

 on and their prostate glands were completely extirpated. Such a complete 

 prostatectomy can be easily performed on rats after a little practice, 

 inasmuch as the glands are comparatively very large and are easily reached. 

 For control experiments another series of rats of approximately the same 

 age were anesthetized with ether in exactly the same manner ; their abdo- 

 mens were opened, and the prostate glands inspected but not excised, and 

 the wounds were closed. The two groups of rats were then allowed to 

 recover completely and after a period of several months all of the rats 

 were trained in the maze. It was found, on checking up all the experi- 

 ments, that complete prostatectomy produced no change in the mental 

 efficiency ("behavior") of the animals. In another series of rats the ani- 

 mals were first trained arid their prostates were excised after learning the 

 problem. It was found in this case also that after the recovery from 

 operation the prostatectomized animals were not less efficient than those 

 in which a simple laparotomy was performed as a control. As a result 

 of this rather painstaking research, the authors are led to conclude that 

 extirpation of the prostate gland exerts no effect on the behavior of young 

 adult rats. 



