312 GENERATION. 



nancy. It will be remembered that the corpus luteum of men- 

 struation is at its maximum of development at the end of 

 about three weeks, when it measures half an inch in depth by 

 three-quarters of an inch in length ; that it then begins to 

 retract, and becomes a small cicatrix at the end of seven or 

 eight weeks. 



In 1851, Dr. J. C. Dalton published an essay on the 

 " Corpus Luteum of Menstruation and Pregnancy," in which 

 he pointed out very accurately the different points of distinc- 

 tion between what had been known as the false and the true 

 corpora lutea. These observations it is unnecessary to quote 

 in detail, as the results were almost identical with those ob- 

 tained by Coste ; but they are peculiarly interesting, not only 

 from the accuracy of the descriptions, but as they were made 

 independently, and without any knowledge of the publication 

 by Coste, four years before. 1 



1 DALTON, Prize Essay on the Corpus Luteum of Menstruation and Pregnancy. 

 Transactions of the American Medical Association, Philadelphia, 1851, vol. iv., 

 p. 647, et seq. 



In a note appended to this essay, Dr. Dalton refers to Longet's Physiology 

 (Paris, 1850), in which the distinction between the two varieties of corpora lutea 

 is made ; but his own investigations, which are remarkable for their complete- 

 ness and accuracy, were made independently and without any knowledge of the 

 observations by Coste. Dr. Dalton's researches on this subject have been exten- 

 sively quoted, have done much to settle the important question of the exact dis- 

 tinctions between the corpora lutea of menstruation and of pregnancy, and at 

 once established his reputation as an accurate and trustworthy observer. The 

 views of Coste were then almost unknown in this country. 



