THE SEXUAL ORGANS. 251 



When the Graafian follicles approach the time of bursting, 

 they gradually enlarge to a circumference of 4'" to 6'" and 

 more, and are continually brought more and more near to the 

 surface, until they project beyond it, as wartlike or hemi- 

 spherical elevations, covered only by a thin pellicle of the much 

 attenuated t. albuginea, with its peritoneal lamella. At the 

 same time their vessels are remarkably multiplied, and by the 

 continual exudation from them, the liquor folliculi is rendered 

 more and more abundant, whilst the fibrous coat of the fol- 

 licle, at the bottom and sides, but not where the ovulum is 

 situated, becomes thickened towards the interior ; the membrana 

 granulosa also swells a little, and contains larger cells (up to 

 O'Ol"'). When these processes have advanced to a certain 

 point, the thin, opposing coats can no longer withstand the 

 continued and ever-increasing pressure from the interior of the 

 follicle ; they give way at the most elevated, and most thinned 

 point, exactly where the ovulum is situated, and this body sur- 

 rounded by the cells of the germinal eminence, if the oviduct 

 has applied itself exactly over the follicle, escapes into it. But 

 the vital course of the Graafian follicle is not hereupon con- 

 cluded, for now a series of partly new formations is presented 

 in it, in consequence of which it at first becomes a corpus 

 luteunij as it is termed and ultimately, disappears altogether. 



These corpora lutea are displayed in the most complete 

 state, when conception and pregnancy ensue upon the detach- 

 ment of the ovum and, when in perfection, appear as roundish 

 or oval, firm bodies, mostly rather larger than the former folli- 

 cles, and are usually visible even on the exterior, as projections, 

 exhibiting on the summit a stellate cicatrix , arising from the 

 rupture of the Graafian follicle. Exteriorly these bodies are 

 bounded, towards the stroma of the ovary, by a thin whitish 

 fibrous membrane (fig. 266, 2/), succeeded by a yellowish vas- 

 cular lamella, which is much plicated, and consequently appears 

 thicker (fig. 266 c) ; and in the interior is a larger or smaller 

 cavity filled, either with coagulated blood (blood-clot), or with 

 a somewhat gelatinous fluid tinged with blood (fig. 266 d e). 

 With respect to the origin of these bodies, it is easily percepti- 

 ble, that their e nucleus' or contents consist of the blood poured 

 out upon the rupture of the follicle, frequently mixed with some 

 remains of the liquor folliculi, and that the outer fibrous mem- 



