EXPERIMENTAL PRODUCTION OF HYPOTYPICAL OVARIES. 1 1 1 



effects of the underfeeding on the ovaries, our experiments suggest 

 very strongly that in addition to the relative loss in weight two 

 other factors may be of significance, viz., first the length of time 

 during which the loss of weight occurs. It seems that more 

 than six days must elapse, before hypotypical ovaries are found. 

 And secondly, the weight of the animal at the beginning of the 

 experiment is of importance. The more the animal approaches 

 full size, the greater is the difficulty with which the changes in 

 the ovaries set in. They are more readily produced in animals 

 weighing between 300 and 400 grams than in animals weighing 

 over 400 grams. But they can be produced in the latter. The 

 effects on the ovaries are therefore to some extent parallel to the 

 effects of undernourishment on the general condition of the ani- 

 mals. Heavier guinea pigs who suffer the same percentage in 

 loss of weight as smaller animals are apparently very much less 

 affected by it as far as their general health is concerned. It is 

 probable that the greater the portion of the food intake is which 

 the animals have to set apart for growth, the more the portion 

 to be used for maintenance is diminished and it seems furthermore 

 that the effect on the general health and on the condition of the 

 ovaries depends upon the portion available for maintenance. 

 The state of the ovaries determines the condition of the uterus, 

 which is always in a resting, almost atrophic condition in cases 

 in which the ovaries are hypotypical. In a similar manner the 

 condition of the mammary gland depends upon the state of the 

 ovaries. We see then that as a result of underfeeding there 

 takes place an increased destruction of granulosa cells which 

 affects even follicles of small or small-medium size. This de- 

 generation of the granulosa cells at such an early stage of the 

 development of the follicles does not occur in the form of a 

 massive destruction, but here and there cells in the rows of the 

 granulosa adjoining the cavity of the follicles are dissolved. 

 While we may notice cells in which the nuclei undergo karyor- 

 rhexis, it is probable that other cells perish without a distinct 

 karyorrhexis taking place. If, on the other hand, a degenera- 

 tion sets in in the larger follicles in normal ovaries, a large 

 number of granulosa cells are destroyed simultaneously and 

 the nuclei of all these cells show karyorrhexis. 



We must therefore assume that if the amount of available food 



