780 GENERATION. 



to this process ; one, in which it is supposed that the fimbriated extremities 

 of the Fallopian tubes, at the time of rupture of the Graafian follicles, be- 

 come adapted to the surface of the ovaries ; and the other, that the ova are 

 carried to the openings of the tubes by ciliary currents. Neither of these 

 theories, however, is susceptible of actual demonstration ; and their value is to 

 be judged from anatomical facts. It is not difficult to understand, taking 

 into account the situation of the ovaries and the relations of the Fallopian 

 tubes, how an ovum may pass into the tube, without invoking the aid of 

 muscular action. It may be supposed, for example, that a 'Graafian follicle 

 is ruptured when the fimbriated extremity of the tube is not applied to the 

 surface of the ovary. One of the fimbrise, longer than the others, is at- 

 tached to the outer angle of the ovary and presents a little furrow, or gutter, 

 leading to the opening of the tube. This furrow is lined by ciliated epithe- 

 lium, as indeed, is the mucous membrane of all of the fimbriae, the move- 

 ments of which produce a current in the direction of the opening, which 

 would apparently be sufficient to carry the ovum into the tube. At the same 

 time there probably is a constant flow of liquid over the ovarian surface, 

 directed by the ciliary current toward the tube ; and when the liquid of the 

 ruptured follicle is discharged this, with the ovum, takes the same course 

 (Becker). This probably is the mechanism of the passage of the ova into 

 the Fallopian tubes ; and it is possible that the fimbriated extremity may be 

 drawn toward the ovarian surface, although it is difficult to understand how it 

 can be closely applied to the ovary and exert any considerable pressure upon 

 the distended follicle. It is proper to note, also, that the conditions depend- 

 ent upon the currents of liquid directed by the movements of cilia are con- 

 stant and could influence the passage of an ovum at whatever time it might 

 be discharged, while a muscular action would be more or less intermittent. 



Puberty and Menstruation. At a certain period of life, usually between 

 the ages of thirteen and fifteen, the human female undergoes a remarkable 

 change and arrives at what is termed the age of puberty. At this time there 

 is a marked increase in the general development of the body ; the limbs be- 

 come fuller and more rounded ; a growth of hair makes its appearance upon 

 the mons Veneris ; the mammary glands increase in size and take on a new 

 stage of development ; Graafian follicles enlarge, and one or more approach 

 the condition favorable to rupture and the discharge of ova. The female 

 becomes capable of impregnation, and continues so, in the absence of patho- 

 logical conditions, until the cessation of the menses. 



The age of puberty is earlier in warm than in cold climates ; and many 

 instances are on record in which the menses have appeared exceptionally 

 much before the usual period. Generally at the age of forty or forty-five, 

 the menstrual flow becomes irregular, occasionally losing its sanguineous 

 character, and it usually ceases at about the age of fifty years. It is said that 

 sometimes the menses return, with a second period of fecundity, though this 

 is rare. According to most writers, while climate has a certain influence 

 over the time of cessation as Avell as the first appearance of the menses, this 

 is not very marked. When the menses appear early in life, they usually 



