OVULATION AND MENSTRUATION 
G5 
made by gynaecological surgeons in the course of operation, viz., that 
apparently ripe or recently ruptured Graafian follicles are found in the 
ovary at any point of the intermenstrual period, and that, on the other 
hand, there is frequently no trace of either ripe or recently ruptured follicles 
immediately before or immediately after the menstrual period. It would 
therefore appear possible that the disappearance of a fixed oestrus in the 
human female has been associated with severance of ovulation from oestrus, 
but it is probable that the most favourable circumstances for successful 
impregnation, are ovulation about the period of menstruation, and in¬ 
semination shortly before or after the period of discharge. 
On the other hand it is absolutely certain that if the table be 
correct, imbedding occurs quite independently of the menstrual growth, 
and at any period in the cycle save the destructive phase. 
In the menstruation of monkeys, according to Heape, “ the stage of 
growth ” is characterised by, firstly, swelling of the endometrium, pro¬ 
liferation of the inter-glandular tissue elements, congestion, and later an 
increase in the number of the leucocytes visible in the blood-vessels. In 
the first stage of degeneration all these phenomena become more pronounced, 
and extravasation of blood takes place into the tissues with migration of 
leucocytes. In other words, the phases represent the early stages of that 
reaction of the tissues in response to stimulus which is called inflammation. 
In the later stages the degenerative changes in the tissue elements, the 
haemorrhage, and the disintegration of the membrane which follows, 
constitute a form of ulceration of the endometrium which can scarcely be 
characterised as other than severe. The discharge contains red-blood 
corpuscles, masses of uterine stroma, fragments of uterine epithelium, 
squamous cells from the vagina, leucocytes and blood-clot in somewhat 
varying amount; in short, the elements are the same as are found 
in a human menstrual discharge, where the reaction has been intense, and 
accompanied by the shedding of membrane. 
The swollen endometrium is described by Heape as menstrual de¬ 
cidua, following the usual custom of obstetricians and pathologists. The 
decidua of pregnancy, so far as we can judge from the limited amount 
of material belonging to the early stages which w 7 e possess, is very 
