THE FEMALE GENITAL ORGANS. 



875 



The term corpus luteum is given to the cicatrix resulting from the rupture of 

 the ovisac. 



The progress of the phenomena of hypertrophy and regression is much 

 slower when the escape of the ovulum has been followed by impregnation ; 



Fisr. 408. 



Fig. 409. 



CONSTITUENT PARTS OF MAMMALIAN OVUM. 



Fig. 408, Entire ovum ; Fig. 409, Ovum ruptured, with the contents escaping ; mv, Vitelline 

 membrane ; j, Yolk ; vg, Germinal vesicle ; tg t Germinal spot. 



so that we have false corpora lutea (those which are independent of preg- 

 nancy), and true corpora lutea, those of gestation, and which do not disappear 

 until several weeks after parturition. (The true corpora lutea are recog- 



Fig. 410. 



SUCCESSIVE STAGES IN THE FORMATION OF THE CORPUS LUTEUM IN THE GRAAFIAN 

 FOLLICLE OF A SOW; VERTICAL SECTION. 



a, The follicle immediately after the expulsion of the ovum, its cavity being filled 

 with blood, and no ostensible increase of its epithelial lining having yet taken 

 place ; at 6, a thickening of this lining has become apparent ; at c, it begins to 

 present folds which are deepened at d. and the clot of blood is being absorbed and 

 decolorized ; a continuance of the same process, as shown at e, /, g, h, forms the 

 corpus luteum, with its stellate cicatrix. 



nisable, after parturition, as small white or dark-coloured masses, the corpora 

 albicans vel nigrum. The yellow colour to which they owe their name is 

 due to the infiltration of the cylindrical cells with fat.) 

 Such are, very briefly, the functions of the ovary. 



