v GENERATIVE SYSTEM OF THE FEMALE 187 



increase the erection of the clitoris, as well as that of the bulbs, by- 

 compressing the effluent veins of these organs. They may also 

 favour ejaculation by pressure on the vestibular glands of Bartholin. 

 A peculiarity worthy of note is that the clitoris in becoming turgid 

 and rigid does not rise upwards like the penis, but lengthens below 

 towards the vaginal orifice (as Fig. 69 shows), placing itself in 

 contact with the dorsal surface of the penis during coitus and 

 receiving the repeated friction which for the woman is the principal 

 source of voluptuousness. 



With the prolongation of coitus, and the voluptuous sensation, 

 the reflex movements extend to all the muscular parts of the 

 female genital apparatus : the bulbo-cavernosus muscles contracting 

 rhythmically constrict the vulvar cleft (whence the name of 

 constrictor cunni) compressing rhythmically the root of the penis 

 and prolonging its erection, whilst the spastic contraction of the 

 muscular layers of the vagina compress it around in all its length. 

 In those women who are most sensitive, the acute paroxysm of 

 voluptuousness which determines these reflexes arises after 

 spermatic ejaculation has happened in the man, and causes a 

 prolongation of the copulation, rendering extraction of the penis 

 from the vagina occasionally difficult and even painful. 



In some animals, for example in dogs, this phenomenon is 

 always much accentuated, and causes prolongation of the copula- 

 tion for some minutes after the embrace a posteriori has ceased, 

 and when the two conjoined individuals are separated violently, 

 there is great pain occasioned, specially to the male. This is due 

 to the extraordinary development of the glans, in comparison with 

 the corpora cavernosa of the penis of the dog, with the result that, 

 being wedged in the vagina, it cannot be withdrawn until the 

 spasm of the constrictor vulvae has ceased. 



V. The fertilisation of the ovum is dependent on its impregna- 

 tion with the sperm, or more strictly the meeting of the male 

 element or spermatozoon with the ovum or female element. It is 

 necessary, therefore, to make clear the mechanism by which the 

 sperm ejaculated from the -penis in the vagina is able to reach the 

 ovum, which has escaped in consequence of the bursting of an 

 ovarian follicle. 



By what process do the spermatozoa penetrate into the 

 uterus and the oviduct to reach the ovum? The sperm cannot 

 be injected directly into the womb through the cervical canal, 

 because normally the axis of this canal forms almost a right angle 

 with the vaginal axis, in the direction, from which ejaculation 

 takes place (Fig. 59). On the other hand, the sperm cannot 

 remain for any length of time in the vagina, because the sperma- 

 tozoa, owing to the acid surroundings, suspend their movements, 

 and after a short time lose the capacity altogether. If we 

 consider the orifice of the uterus, through which the sperm must 



