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CORTEX 



author 198 and by Sisson and March. 577 The latter authors 

 found the following survival periods: 



Immature animals survive for a period of time which is 

 only about one-half as long as the survival time of adult animals. 



Pre-operative care. The pre-operative care is of utmost im- 

 portance in determining the survival period after adrenalec- 

 tomy. Animals obtained from sources in which temperature 

 conditions, food, etc., are not optimal succumb much more 

 quickly than those maintained under good conditions and in 

 a good state of health and nutrition. This is illustrated by the 

 following experiment : A series of six cats were subjected to a 

 room temperature of 10°C. for several days before the removal of 

 the right adrenal. Such animals normally survive unilateral 

 adrenalectomy without manifesting any signs of insufficiency. 

 The cats of this series, however, all showed signs of adrenal 

 insufficiency, and four of them died within ten days following 

 the unilateral adrenalectomy. 198 



Anesthetic. The anesthetic used and the duration of the 

 anesthesia have an important bearing on the survival period of 

 animals after adrenalectomy. Some of the long survivals 

 reported by earlier workers are perhaps to be attributed to 

 their avoidance of any anesthetic. That the duration of the 

 period of anesthesia is of great importance is demonstrated by 

 the following experiment: The average survival of five rats 

 receiving ether for five minutes was fourteen days, while in 

 five animals receiving ether for ten minutes the average survival 

 period was only seven days or only half as long as in the first 

 group. 198 



In general, the use of ether as an anesthetic results in sur- 

 vival periods which are much shorter than those obtained when 

 certain other anesthetics are used. Thus in dogs, Firor and 



