572 THE HUMAN BODY 



the discus proligerus. The emptied follicle becomes filled up with 

 a reddish-yellow mass of cells, and constitutes the corpus luteum, 

 which recedes again to the interior of the ovary and disappears in 

 three or four weeks, unless pregnancy occur; in that case the corpus 

 luteum increases for a time, and persists during the greater part of 

 the gestation period. 



The discharged ovum enters the Fallopian tube and passes down 

 it to the uterus. Just how the passage from the ovary to the tube 

 occurs is not clear, although it is suggested that the cilia which 

 line the tube set up by their motion a current sufficient to convey 

 the ovum across the intervening space and into its mouth. Having 

 entered the Fallopian tube the egg slowly passes on to the uterus, 

 moved by the cilia lining the oviduct; its descent probably takes 

 about four or five days; if not fertilized, it dies and is passed out. 



Menstruation. Ovulation occurs during the sexual life of a 

 healthy woman at intervals of about four weeks, and is attended 

 with important changes in other portions of the generative ap- 

 paratus. The ovaries and Fallopian tubes become congested. 

 The mucous membrane of the uterus at or just before the periods 

 of ovulation becomes swollen and soft, and minute hemorrhages 

 occur in its substance. The superficial layers are broken down, 

 and discharged along with more or less blood, constituting the 

 menses, or monthly sickness, which commonly lasts from three to 

 five days. During this time the vaginal secretion is also increased, 

 and, mixed with the blood discharged, more or less alters its color 

 and usually destroys its coagulating power. Except during preg- 

 nancy and while suckling, menstruation occurs at the above in- 

 tervals, from puberty up to about the forty-fifth year; the periods 

 then become irregular, and finally the discharges cease; this is an 

 indication that ovulation has come to an end, and that the sexual 

 life of the woman is completed. This time, the climacteric or " turn 

 of life," is a critical one; various local disorders are apt to super- 

 vene, and even mental derangement. 



Hygiene of Menstruation. During menstruation there is apt 

 to be more or less general discomfort and nervous irritability; the 

 woman is not quite herself, and those responsible for her happiness 

 ought to watch and tend her with special solicitude, forbearance, 

 and tenderness, and protect her from anxiety and agitation. Any 

 strong emotion, especially of a disagreeable character, is apt to 



