]}Y F. P. 8AXDES. 405 



A similarity in the general arrangement of the cells in the three is notice- 

 able. The central corpus luteum shows in the cavity an ovum whose envelope 

 is crumpled. The membrana granulosa is beginning to hypertrophy, and 

 encroaches on the central cavity, particularly on the right hand side. 



Plate xix. 



Fig. 23. — A " corpus luteum atreticum " at about the stage represented in 

 fig. 18. 



Note the degenerated ovum towards the centre of the structure. It is 

 placed against the left wall of the largest vascular space. Other vascular 

 spaces lined by endothelium are also well seen, as well as the general 

 similarity between this figure and fig. 13. 



Plate XX. 



Fig. 24 represents a "corpus luteum atreticum." This figure should be 

 compared with fig. 14. The similarity in the structure of the two is note- 

 worthy. 



In the centre of the field is seen the remnant of the atrophied ovum 

 invaded by leucocytes. Round this the "corpus luteum atreticum" has 

 formed, and is exactly similar to the " corpus luteum verum." This figure 

 illustrates the general dilatation of the blood vessels round the corpus luteum, 

 and also the thinning of the ovarian stroma generally, with portions of 

 corpora lutea on either side of the corpus luteum atreticum. 



