I 88 LEO LOEB. 



nants of former corpora lutea. There are in the cortex a number 

 of primordial follicles developing into small Graafian follicles 

 and into follicles of small to medium size. But before they have 

 hardly reached the latter size, a slow solution of the granulosa 

 sets in and very soon the cavity of the follicles is lined by the 

 theca interna. 



The further course of the atresia of the follicles is, however, 

 changed; the connective tissue does not as usual grow into the 

 follicular cavity; instead the atretic follicles present themselves 

 as small cysts. The ordinary follicles in various stages of con- 

 nective tissue atresia are therefore lacking. There is, however, 

 present a very large number of follicles in the last stage of atresia, 

 a cavity with remnants of the zona pellucida, or merely a small 

 cavity surrounded by a thick layer of the shrunken theca interna 

 cells. By far the greater part of the ovaries consists of such 

 follicles in the last stage of atresia ; the proportion of such follicles 

 is much greater in this animal than in normal ovaries which are 

 in the period following the first week of ovulation and even 

 larger than in the other hypotypical ovaries which we observed. 

 There are two further peculiarities noticeable in these ovaries, 

 viz., (i) a relative decrease in the amount of fibrous tissue which 

 surrounds the various follicles, and (2) the presence of numerous 

 follicles with multiple eggs. While we observe around a number 

 of growing or atretic follicles a fibrous membrane, the latter is 

 always thin andit is absent around other follicles. Not rarely we 

 see twoadjoining folliclesof small to medium size merely separated 

 by several rows of relatively large theca interna cells; or we 

 see small follicles close together, and not separated by fibrous 

 tissue; at other places the theca internae of two quite atretic 

 follicles press on each other, the theca cells of the one follicle 

 surrounding directly the capillaries of the theca interna of the 

 adjoining follicle. In other cases two or three shrunken egg 

 cavities are enclosed in one mass of small theca interna cells. 

 If we compare the amount of fibrous tissue separating the 

 follicles in this animal and in other animals with either normal 

 or hypotypical ovaries, we find in the ovaries of other guinea 

 pigs a larger amount of fibrous stroma separating the various 

 follicles. This decrease in fibrous tissue made it possible to 



