390 THE PHYSIOLOGY OF REPRODUCTION 



for distinguishing whether the total daily.metabolism, which in some 

 cases has been shown to become diminished after castration, does so 

 in consequence of a variation in temperament (or greater tendency 

 towards physical repose), or whether the oxidation of the resting cell 

 (i.e. the fundamental metabolism) is reduced. He is disposed to 

 believe that the marked diminution in the respiratory exchange 

 which has been observed in some animals after castration is probably 

 due to a greater indolence, and is, therefore, an indirect result. 

 Moreover, he points out that, in the case of Liithje's castrated dogs, 

 which did not exhibit any change from their normal habits and 

 movements, there was no diminution in the gaseous exchange as 

 compared with control animals. 



Loewy and Richter,^ however, have arrived at different conclusions, 

 finding pronounced reduction in the respiratory metabolism of castrated 

 dogs of both sexes. Furthermore, these investigators found that after 

 feeding the female animals upon ovarian substances there was a great 

 increase in the metabolism, a castrated bitch showing an increase of 

 from thirty to fifty per cent, above the normal values observed before 

 the operation. Testicular substance had no. influence upon any of 

 the castrated animals, while normal animals did not react at all either 

 to ovarian or to testicular extracts. Loewy and Richter suggest that 

 the ovaries produce a specific substance which promotes oxidation in 

 the body. 



Zuntz ^ has investigated the gaseous metabolism in four castrated 

 women, and found that it lay within the limits of the normal. It is 

 to be noted that neither of these women showed any tendency to 

 corpulence. These observations support the view that when castrated 

 animals show a reduction in the respiratory exchange, this is an 

 indirect effect resulting from greater indolence of disposition. On 

 this view, also, the tendency towards a deposition of fat on the 

 part of many castrated animals is to be attributed to the same 

 cause. 



Dr. Cramer,^ working in conjunction with the author, has lately 

 investigated the respiratory metabolism of a number of rats whose 

 ovaries had been removed some time previously, and in these animals 

 it was found that the gaseous exchange lay within the limits of the 

 normal, thus confirming Zuntz's experience with castrated women. 

 It is possible, however, that the results of castration were obscured 

 by other factors. In this investigation the apparatus employed by 

 Haldane and Pembrey was used in preference to that of Zuntz. We 



' Loewy and Eichter, " Sexual-Funktion und Stoffwechsel," Arch. f. Physiol., 

 Supplement, 1899. 



2 Zuntz, " Gaswechsel bei Kastrierten Frauen,'' VerharuU. d. Oyndk. OeselL, 

 Berlin, 1904. See also Deutsch. ZeiUoh. f. Chir., vol. 65, 1908. 



^ Cramer and Marshall. MS. unpublished. 



