§ 2 HISTOGENESIS OF CORPORA LUTEA 89 



and GOLGI bodies. These new substances arise at first from 

 small albuminous granules at whose surface numerous 

 exceedingly small drops of fat may be found. These albumin- 

 fat systems, which we consider to be the forerunners of the 

 hormonal products, dissolve during the course of the further 

 development of the corpus luteum and finally appear as 

 vacuoles in the cytoplasm of the granulosa cells; thus, their 

 whole appearance is similar to that of the "lutein-cells" of the 

 corpora lutea of mammals. 



The further these lutein-cells penetrate into the ovular 

 space the greater their distance from the blood-vessels and 

 lymph-sacs becomes, and the more difficult the emission of 

 the accumulated hormonal substances. This difficulty arises 

 soon after the separation of the daughter-cells, with the result 

 that these cells become charged with numerous vacuoles and 

 expand considerably. In several places the strongly vasicul- 

 arised theca breaks through the granulosa and penetrates into 

 the follicular space filled with lutein cells (Fig. 66). The 

 long reel-shaped theca cells mix with the large lutein cells 

 and form — as in the case of the mammalian corpus luteum 

 — a connective tissue framework, around which the horm- 

 one-forming cells group themselves. Bloodvessels appear in 

 the theca tissue if the ovary is stimulated (e.g., by injection 

 of an extract from the hypophysis of the carp) and there 

 follows active formation of corpora lutea; then the blood- 

 vessels of the theca and those in the follicular space are filled 

 to capacity, which may lead to large extravasates. Even 

 macroscopically these blood-filled follicles may be distin- 

 guished as red blood-points. 



Simultaneously with the invasion of the theca cells other 

 granulosa cells, which have not participated in the phago- 

 cytosis of the yolk, and possess a dense cytoplasm, penetrate 

 into the corpus luteum space and clear away any oolemma 

 remnants that have not yet been dissolved (Fig. 66, below). 

 The arrival of these cells results in a dense mass of tissue 

 which grows around the oolemma remains in concentric 

 layers. Thereby so-called "cell-pearls" are formed, which 

 finally, by fusion and increase in size, grow into cystoid 



