THE EFFECT OF CASTRATION, SPAYING OR SEMI- 

 SPAYING ON THE WEIGHT OF THE CENTRAL 

 NERVOUS SYSTEM AND OF THE HYPOPHYSIS OF 

 THE ALBINO RAT; ALSO THE EFFECT OF SEMI- 

 SPAYING ON THE REMAINING OVARY 



SHINKISHI HATAI 



The Wistar Institule of Anatomy and Biology 



The object of the present paper is to report on the condition 

 of several of the internal organs of the albino rat after castration, 

 spaying or semi-spaying. These series of spayed and semi-spayed 

 animals were prepared by Dr. Stotsenburg and have been used 

 by him for studying the growth of the body in weight as affected 

 by the respective operations (Stotsenburg '13). The castration 

 of the animals here used was also performed by Dr. Stotsenburg 

 but in this series the growth of the body was not followed, 

 the effect of this operation having been previously determined 

 (Stotsenburg '09). 



I wish to acknowledge the courtesy 'of Dr. Stotsenburg in 

 allowing me to make the postmortem examinations in all of these 

 interesting cases. 



All the necessary details concerning the operations and the 

 care of the animals have been already given by Stotsenburg 

 ('09, '13) but two points should be mentioned here as these are 

 important for the interpretation of the results: (1) in all instances 

 the operation was perfonned on young rats about a month old 

 and (2) in the cases of castration the testes with epididymis were 

 removed. 



Regarding the method of examination of the various organs, 

 as well as the significance of the various formulas used in determin- 

 ing the calculated values from the observed values, the reader 

 is referred to a paper published recently by myself (Hatai, '13). 



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