202 Mr. W. Heape. 



" The Menstruation and Ovulation of Macacus rhesus" By 

 WALTER HEAPE, M.A., Trinity College, Cambridge. Com- 

 municated by Dr. M. FOSTER, Sec. R.S. Received June 

 15, Read June 18, 1896. 



(Abstract.) 



The specimens used in the following investigation were collected 

 in Calcutta in 1891. 



Anatomy of the Cervix. A valve-like structure is formed in the 

 canal of the cervix by means of three strong folds, one of these folds 

 fits into a recess formed by the two other folds, and forms a valve 

 which persists throughout life. It is unlike any other structure of 

 the cervix with which I am acquainted. 



Breeding. A definite breeding season for Macacus rhesus seems to 

 be proved, but it is equally certain that in different parts of the 

 Continent of India the breeding season occurs at different times of 

 the year. 



Menstruation. A congestion of the skin of the abdomen, legs, and 

 tail, a swelling and congestion of the nipples and vulva, and flushing 

 of the face, are all prominent external signs of menstruation. A 

 regular menstrual flow occurs consisting of a viscid, stringy, opaque 

 white fluid filled with granules, and containing also red blood 

 corpuscles, pieces of uterine tissue, both stroma and epithelium, and 

 also leucocytes. 



The following classification of the various stages passed through is 

 adopted : 



A. Period of rest. Stage I. The resting stage. 



B. Period of growth. Stage II. The growth of stroma. 



Stage III. The growth of vessels. 



C. Period of degeneration. 



Stage 1Y. The breaking down of vessels. 

 Stage Y. The formation of lacunae. 

 Stage YI. The rupture of lacunae. 

 Stage VII. The formation of the menstrual 

 clot. 



D. Period of recuperation. 



Stage VIII. The recuperation stage. 



The surface of the uterine mucosa, which is smooth and semi- 

 transparent during Stage I, becomes swollen and opaque during 

 Stage II. and flushed during Stage III ; it then becomes highly con- 

 gested, Stage IV, and dark red spots, due to the formation of lacunae, 

 appear on the surface in Stage V ; when Stage VI is reached, free 



