876 GENERATION". 



quantity of vaginal mucus, which becomes brownish or rusty in color. It is probable 

 that, at this time, the discharge has a peculiar odor, though this point is somewhat diffi- 

 cult to determine. In the lower animals, at least, there is certainly a characteristic odor 

 during the rutting period, which attracts the male. At this time, also, the breasts be- 

 come slightly enlarged in the human female, showing the connection between these 

 organs and the organs of generation. This stage may continue for one or two days, 

 although, in many instances, the first evidence of the access of a period is a discharge 

 of blood. 



When the general symptoms above indicated occur, the sense of uneasiness is usually 

 relieved by the discharge of blood. During this, the second stage, blood flows from the 

 vagina in variable quantity, and the discharge continues for from three to five days. 

 With regard to the duration of the flow, there are great variations in different individu- 

 als. Some women present a flow of blood for only one or two days ; while, in others, 

 the flow continues for from five to eight days, within the limits of health. A fair aver- 

 age, perhaps, is four days. 1 It is also difficult to arrive at an approximation, even, of the 

 total quantity of the menstrual flow. Burdach estimated it at from five to six ounces. 

 According to Longet, this estimate is rather low, the quantity ordinarily ranging from 

 ten to twelve ounces, occasionally amounting to seventeen ounces, or even more. It is 

 well known that the quantity is exceedingly variable, as is the duration of the flow, 

 and the difficulties in the way of collecting and estimating the total discharge are 

 evident. 



The characters of the menstrual flow are sufficiently simple. Supposing the discharge 

 to continue for four days, on the first day, the quantity is comparatively small ; on the 

 second and third, the flow is at its height ; and the quantity is diminished on the fourth 

 day. During this, the second stage, the fluid has the appearance of pure arterial blood, 

 not coagulated, and mixed, as has been shown by microscopical examination, with pave- 

 ment-epithelium from the vagina, cylindrical cells from the uterus, leucocytes, and a 

 certain amount of sero-mucous secretion. Chemical examination of the fluid does not 

 show any marked peculiarities, except that the quantity of fibrin is either not estimated 

 or is given as much less than in ordinary blood. 



The mechanism of the haemorrhage, which will be considered more fully when we 

 come to study the changes in the uterine mucous membrane during menstruation, 

 is probably the same as in epistaxis. There is a rupture of small blood-vessels, prob- 

 ably capillaries, and blood is thus exuded from the entire surface of the membrane 

 lining the uterus, and sometimes from the membrane of the Fallopian tubes. The 

 blood is then discharged into the vagina and is kept fluid by the vaginal mucus. 

 The mucus of the body of the uterus is viscid and alkaline; the mucus secreted at 

 the neck is gelatinous, viscid, tenacious, and also alkaline ; the vaginal mucus is decid- 

 edly acid, creamy, and not viscid, containing numerous cells of scaly epithelium, and 

 leucocytes. 



The third stage, that of cessation of the menses, is very simple. During the latter 

 part of the second stage, the flow of blood gradually diminishes ; the discharge becomes 

 rusty, then lighter in color ; and, in the course of about twenty-four hours, it assumes 

 the characters observed in the intermenstrual period. 



When the menstrual flow has become fully established, there is no very marked gen- 

 eral disturbance, except a sense of lassitude, which may become exaggerated if the dis- 

 charge be unusually abundant. It has been noted, however, by Eabuteau, that, during 

 the menstrual period, the production of urea is diminished more than twenty per cent., 

 that the pulse becomes slower, and that the temperature falls at least one degree (half 

 a degree, centigrade). 



1 Burdach makes the following 1 statement with regard to certain conditions capable of modifying the menstrual 

 flow: "The flow is more abundant in the indolent than in women accustomed to labor; in those of feeble con- 

 stitution than hi those who enjoy robust health ; in inhabitants of cities than in inhabitants of villages." 



