LVIIL] 



THE CORPUS LUTEUM 



823 



ends of the Fallopian tube and thence passes to the uterus. The 

 bursting of a Graafian follicle usually occurs about the time of men- 

 struation. 



After the bursting of a Graafian follicle, it is filled up with what 

 is known as a corpus luteum. This is derived from the wall of the 



FIG. 616. Corpora lutea of different periods. B, Corpus luteum of about the sixth week after impreg- 

 nation, showing its plicated form at that period. 1, Substance of the ovary ; 2, substance of the 

 corpus luteum ; 3, a greyish coagulum in its cavity. (Paterson.) A, Corpus luteum two days after 

 delivery ; D, in the twelfth week after delivery. (Montgomery.) 



follicle, and consists of columns of yellow cells developed from the 

 yellow cells of the membrana granulosa ; it contains a blood-clot in 

 its centre. These cells multiply, and their strands get folded and 

 converge to a central strand of connective tissue; between the 

 columns there are septa of connective tissue with blood-vessels. The 

 corpus luteum after a time gradually disappears ; but if pregnancy 

 supervenes it becomes larger and more persistent (see fig. 616). The 

 following table gives the chief facts in the life-history of the ordinary 

 corpus luteum of menstruation, compared with that of pregnancy : 



At the end of 



three weeks. 



One month , 



Two months . 



Six months 



Nine months . 



Corpus Luteum of 

 Menstruation. 



Three-quarters of an inch 



convoluted wall pale. 

 Smaller ; convoluted wall 



bright yellow; clot still 



reddish. 

 Reduced to the condition 



of an insignificant cica- 



trix. 



Absent. 



Corpus Luteum of 

 Pregnancy. 



in diameter ; central clot reddish ; 



Larger; convoluted wall bright 

 yellow ; clot still reddish. 



Seven-eighths of an inch in dia- 

 meter; convoluted wall bright 

 yellow; clot perfectly de- 

 colorised. 



Still as large as at end of second 

 month ; clot fibrinous ; convo- 

 luted wall paler. 



One half an inch in diameter; 

 central clot converted into a 

 radiating cicatrix ; the external 

 wall tolerably thick and con- 

 voluted, but without any bright 

 yellow colour. 



