THE CORPUS LUTEUM. 



615 



lutea would be manifestly of the same age and development, and 

 neither of them would resemble the retrograde structures habitually 

 found during menstruation. 



After lactation, the ovaries resume their ordinary function. The 

 Graafian follicles mature and rupture as before, and new corpora lutea 

 follow each other in alternate development and disappearance. 



The corpus luteum of menstruation, therefore, differs from that of 

 pregnancy in development and duration. While the former passes 

 through all the important phases of its growth and decline in a period 

 of two months, the latter lasts from nine to ten months, and presents, 

 during a great portion of the time, a larger size and more solid organ- 

 ization. Even in the corpus luteum of pregnancy, however, the bright 

 yellow color, which is so striking a feature, is only temporary ; not 

 making its appearance till about the end of the fourth week, and again 

 disappearing after the sixth month. 



The following table contains, in a condensed form, the characters of 

 the corpus luteum, in menstruation and pregnancy, at different periods 

 of its development: 



COEPUS LUTEUM OF MENSTRUATION. CORPUS LUTEUM OF PREGNAXC v. 



At the end of 

 three iceeks. 

 One month. 



TTO months. 



Four months. 



Six months. 

 Nine months. 



Twelve by nineteen millimetres in diameter ; central clot red- 

 dish; convoluted wall pale. 



Smaller ; convoluted wall bright 

 yellow ; clot still reddish. 



Reduced to the condition of an 

 insignificant cicatrix. 



Absent or unnoticeable. 



Absent. 



Absent. 



Larger; convoluted wall bright 

 yellow ; clot still reddish. 



Twelve by twenty-two milli- 

 metres in diameter ; convo- 

 luted wall bright yellow; clot 

 perfectly decolorized. 



Eighteen by twenty-two milli- 

 metres in diameter; clot pale 

 and fibrinons; convoluted wall 

 dull yellow. 



Still as large as at the end of 

 the second month. Clot fibri- 

 nous. Convoluted wall paler. 



Ten by thirteen millimetres in 

 diameter; central clot con- 

 verted into a radiating cic- 

 atrix ; external wall still 

 thick and convoluted, but 

 without any bright yellow 

 color. 



