14 THE HUMAN BODY. 



and, commonly, more subcutaneous adipose tissue develops 

 over the Body generally, but especially on the breasts and 

 hips; consequently the contours become more rounded. 

 The external generative organs increase in size, and the 

 clitoris and nymphae become erectile. The uterus grows 

 considerably, the ovaries enlarge, some Graafian follicles 

 ripen, and the events treated of in the succeeding paragraphs 

 occur. 



Ovulation. From puberty; during the whole child- 

 bearing period of life, certain comparatively very large 

 Graafian follicles may nearly always be found either close 

 to the surface of the ovary or projecting on its exterior. 

 These, by accumulation of liquid within them, have become 

 distended to a diameter of about 4mm. (-J- inch); finally, the 

 thinned wall of the follicle gives way and the ovum is dis- 

 charged, surrounded by some cells of 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 occurs; in that case 

 the corpus luteum increases for a time, and persists during 

 the greater part of the gestation period. 



Menstruation, ^y vulation 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 apparatus. \ The ovaries and Fallopian tubes 

 become congested, and the fimbrise of the latter are erected 

 .and come into contact with the ovary so as to receive any 

 ova discharged. Whether the fimbriae embrace the ovary 

 and catch the ovum, or merely touch it at various points 

 and the ova are swept along them by their cilia to the 

 cavity of the oviduct, is not certain. Having entered the 

 Fallopian tube the egg slowly passes on to the uterus, 

 probably 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. In the womb important changes occur at 

 or about the periods of ovulation ; its mucous membrane be- 

 comes swollen and soft, and minute hemorrhages occur in its 

 substance. Unless an impregnated ovum enters the cavity the 

 superficial layers of the uterine mucous membrane are then 



