Cystic Degeneration of the Ovaries 1 63 



atresia of the follicle, since, in this case, indeed, the theca interna becomes 

 extraordinarily thickened yet does not lead to rupture of the follicle be- 

 cause, in that case, the follicular fluid becomes decreased and the pressure, 

 as a consequence, is lessened. 



Zschokke believes that a simple increase of the follicular fluid can not 

 occur through hyperaemia because artificial or inflammatory hyperaemia 

 does not cause ovulation ; on the contrary, it is to be observed that a local 

 hyperaemia which affects the theca folliculi alone evidently exerts a differ- 

 ent influence from an artificial or inflammatory hyperaemia which involves 

 the entire ovary. It is, moreover, to be remarked that the pressure of the 

 follicular fluid in follicles of different sizes is variable in degree because the 

 amount of fluid evidently varies with the size of the follicle, whereas the 

 intrafoUicular pressure alone can have the power to rupture the follicle. 



Zschokke believes also, a conclusion based upon personal observationi 

 that ovulation often occurs in the beginning of estrum and that it is, conse- 

 quently, to be held that the rupture of the follicle occurs, in some cases, 

 before estrum has reached its zenith. We hold, on the one hand, from 

 facts known for many decades, that ovulation, which is to be regarded as 

 the manifestation of vaso-dilation, ushers in estrum ; we might however, 

 on the other hand, emphasize the fact that the most evident normal clinical 

 symptoms of estrum are not to be regarded as occurring at the same moment 

 as the highest degree of ovarian hyperaemia. It seems to us far more 

 probable that hyperaemia of the ovary precedes that of the uterus and 

 vagina and that such a view is more plausible and correct. One argument 

 for this view lies in the fact that, when cows, especially those in pasture, 

 are bred at the beginning of estruni, they become pregnant. 



In regard to ovarian cysts,jste-liave^ottn4-small cystic follicles_in ovaries I 

 of calves,~feiJ:o_tis3KeIdaysx)ld,.JadiiGh-were investigated by Heitz; These / 

 inxgsfi^tions showed that 80 % of the ^varies of -eows-contained.cysts at 

 le ast 3 TQin^_in_diameter! In numeroiis cases, the cysts had a diameter of 

 over 10 mm. and fouFtimes they reached 13 mm. Often there occurred in 

 certain of these ovaries one or more cysts so greatly developed that the 

 prope r tissue_ of the ovary appeared as an unimportant appendix. By micro- i 

 scopical examinaHo B LheMe -were~recognizable as internal folMcletr The " 

 granulosa~exhibited no mar ked chang c a, wh clggs~aegenefaiive^rocesses 

 existed in the egg. These follicles do no t rupture spontan eously, since ^ 

 nowhere could there be seen yellow boaieTor other evidences, like scars or 

 fibrous tufts, which indicated ruptured follicles. Many of these follicles 

 retrograde, many, perhaps, become cysts, because they show absolutely no 

 decrease in size, in spite of the fact that the egg has already undergone 

 serious degeneration. Cysts are not infrequently observed even before the 

 first pregnancy. 



Also, in new-born calves and heifers, one meets, according to Waldeyer 1 

 and others, with follicles as large as peas, containing normally developed 

 ova. The same is true for various . other species of animals. On the 



' Waldeyer in Hertwig's Handbuch der Entwicklungsgeschichte, p. 374. 



