INTERNAL SECRETION OF OVARY 233 



of a pregnant female ; there was a compact gland, rich in blood 

 vessels; the epithelium was full of fat droplets. Also the 

 uterus was in a condition characteristic of pregnancy {Figs. 

 105 A and 106 A). The ovaries were found about three months 

 after irradiation to be smaller than normally; a great many 

 folHcles were atretic, and the number of the interstitial cells 

 was extraordinarily increased. Steinach and Holzknecht 

 mention that the whole stroma of the ovary was transformed 

 into a mass of lutein cells. 



It seems justifiable to conclude from these experiments that 

 the marked development of the mammary gland and of the 

 uterus was caused by an increase of the interstitial tissue 

 derived from the follicles. Such a conclusion seems especially 

 true when comparing these results with those observed in 

 animals where irradiation caused destruction and sclerotization 

 of the whole ovary and at the same time signs of castration. A 

 similar observation was made before by Biedl (2nd ed., p. 337) 

 on the uterus of the rabbit. He stated that sclerotization of 

 the ovary after irradiation is accompanied by an atrophy of 

 the uterus. There is no room for the objection that the highest 

 degree of development which can be attained by the mammary 

 gland and the uterus after irradiation is caused by a direct 

 action of X-rays on these organs, since Steinach and Holzknecht 

 made another experiment in which the ovaries were removed 

 after a great development of the mammary gland had occurred 

 after irradiation; they then observed an atrophy of the 

 mammary gland. 



From all these experiments it is possible to conclude that 

 from the foUicles endocrine cells are, so to speak, poured into 

 the stroma in an increased number, and that consequently 

 the influence of the ovary upon the mammary gland and 

 uterus becomes greater. Steinach speaks of such an irradiated 

 ovary as an isolated endocrine gland; there is in reality no 

 isolation, as ova are still to be found in such an ovary. But 

 this objection does not matter; for in order to reach the above 

 conclusion it is not necessary to suppose that all the ova or 

 folhcles throughout the whole ovary must have disappeared. 

 The conclusion is justified, as it was shown that greater 

 folhcular atresia, and consequently an increased number of 

 interstitial cells, bring about a greater development of the 

 mammary gland and of the uterus, and that this development 



