FECUNDATION. 795 



that venereal excitement in the female facilitates conception, other condi- 

 tions being favorable. When excitement occurs in the female there is en- 

 gorgement of the true erectile tissues and possibly of the convoluted vessels 

 surrounding the internal organs. The neck of the uterus becomes hardened 

 and slightly elongated (Wernich) ; and it has been observed by Litzmann 

 and others, that there occurs a sudden opening and closing of the os, which 

 exerts more or less suction force. These conditions, however, are not essen- 

 tial to fecundation, although they may exert a favorable influence upon the 

 penetration of spermatozoids and may at certain times determine the rupture 

 of a Graafian follicle. 



The spermatozoids, once within the cervix uteri, and in contact with the 

 alkaline mucus, which increases the activity of their movements, may pass 

 through the uterus into the Fallopian tubes, and even to the surface of the 

 ovaries. Precisely how their passage is effected, it is impossible to say. It 

 can only be attributed to the movements of the spermatozoids themselves, to 

 capillary action, and to a possible peristaltic action of the muscular structures ; 

 but these points have not as yet been subjects of positive demonstration. As 

 regards the human female, it is impossible to give a definite idea of the time 

 required for the passage of the spermatozoids to the ovaries or for the de- 

 scent of the ovum into the uterus ; and it is readily understood how these 

 questions hardly admit of experimental investigation. It is known, how- 

 ever, that spermatozoids reach the ovaries, and they have been seen in motion 

 on their surface, seven or eight days after connection. 



Fecundation. The ordinary situation at which the ovum is fecundated 

 is the dilated, or external portion of the Fallopian tube. All authorities are 

 agreed that fecundation does not take place in the cavity of the uterus. In 

 rabbits, when the ovum has descended into the uterus, it is surrounded with 

 a dense, albuminous coating which the spermatozoids can not penetrate 

 (Coste). It is possible that this occurs in the human subject. Cases of 

 abdominal pregnancy show that an ovum may be fecundated on the ovary, 

 as soon as it is discharged from the Graafian follicle. 



The question of the duration of vitality of the spermatozoids, after their 

 passage into the uterus, has an important bearing upon the time when con- 

 ception is most liable to follow sexual intercourse. The alkaline mucus of 

 the internal organs actually favors their movements ; the movements are not 

 arrested by contact with menstrual blood ; and, indeed, when the spermato- 

 zoids are mixed with the uterine mucus, they simply change their medium, 

 and there is no reason to believe that they may not retain their vitality as 

 well as in the mucus of the vesiculse seminales. It seems impossible, there- 

 fore, to fix any limit to the vitality of these anatomical elements, under phys- 

 iological conditions; and it is not certain that spermatozoids may not 

 remain either in the vagina or in the Fallopian tubes and around the ovary, 

 when intercourse has taken place immediately after a menstrual period, 

 until the ovulation following. According to the observations of Bossi, 

 spermatozoids may retain their vitality in the acid mucus of the posterior 

 vaginal cul-de-sac, or nidus seminis, as long as seventeen days. It is prob- 



