ISOLATION OF SEXUAL HORMONES 331 



to a difference in the samples of corpus luteum. He assures 

 us that there are apparently two principles in the corpus 

 luteum having an antagonistic action upon the uterus. Both 

 these principles can be extracted, according to Itagaki, by 

 Locke's solution; the principle causing inhibition of the 

 uterine contractions is soluble in alcohol, the principle causing 

 increase of tone is soluble in water. Athias (1920) has recently 

 confirmed the stimulating action of the ovary and of the 

 corpus luteum on the uterus. 



It may be of interest to note that Weil (1920) recorded a 

 difference in reaction to subcutaneous injections of testicular 

 extracts according to the sex of the injected animal. There 

 was a sudden decrease in the output of COg followed by a 

 sudden increase beyond the normal output in young males, 

 "castrates" and pregnant females, but no influence in adult 

 males and females. On the other hand, ovarian extracts 

 were without any influence on adult males, but caused de- 

 crease and increase in the CO2 output in females and young 

 or castrated males. Weil refers to this as a "sex specific" 

 reaction. 



The experiments of Dittler (1920) may be mentioned here, 

 though only in an indirect relation to the problems discussed 

 in this chapter. Dittler made intravenous injections of fresh 

 sperm into female rabbits and stated that sterility can be 

 caused by repeated injections. Sterility was not caused when 

 the sperm of a man instead of rabbit's sperm was used. This 

 effect is at first thought similar to that caused by injection of 

 extracts of corpus luteum. But there is a very marked differ- 

 ence between sperm and corpus luteum, since sperm does not 

 inhibit ovulation, according to Dittler, whereas the corpus 

 luteum has this effect. 



BIBLIOGRAPHY FOR CHAPTER VII. 



Ancel et BoTJiN. 1906. Action de I'extrait de la glande interstitielle 

 du testicule sur le developpement du squelette et des organes 

 genitaux. G. R. de VAcad. d. Sc, 142, p. 232. 



Athias. 1920. Action d'extraits et produits derives d'organes a 

 secretion interne sur 1' uterus isole, particulierement apres la 

 castration totale. Arch, internat. de Pharmacodynamie et de 

 Therapie, 25, p. 423. 



