GENITAL SYSTEM. 485 



These muscles contract, in virtue of a reflex action (see 

 above), influenced by the irritation of the glans penis, and at 

 each contraction, we might almost say at each pulsation, of 

 the accelerator wince muscle, the glans become more swollen 

 and sensitive ; and its papillae being extended over a larger 

 surface are more highly excited by the continued friction. 

 When this sensation has reached its highest point, it occa- 

 sions the reflex phenomenon of ejaculation. 



C. Ejaculation. 



Ejaculation is the "termination of the venereal act, and ita 

 accomplishment is preceded by numerous accessory acts. 



In the first place, by the fact of erection the urethral canal 

 is dilated and open. This dilatation would naturally produce 

 a certain aspiration or suction, and something must fill the 

 canal which is transformed from a flattened to a cylindrical 

 shape : it has been supposed that air is thus introduced, and 

 this hypothesis would explain also those cases of chancres 

 found in the interior of the urethra ; and assuming that aspira- 

 tion during coitus has sucked into the canal a virulent liquid 

 from the contaminated woman. Yet observation has shown 

 that air does not rush in to fill the enlarged cavity, for in that 

 case particles of air, in the form of bubbles, would be found 

 in the excreted spermatic fluid ; this latter phenomenon has 

 never been observed. Cowper's glands, analogous to the 

 salivary glands, which are situated amongst the striated and 

 smooth muscular fibres of the perineum (middle fascia), and 

 behind the enlargement of the bulbous portion of the urethra 

 (Fig. 131, p. 479), secrete a fluid which would fill the 

 vacuum in the canal ; the excretory duct from these glands 

 opens into the urethra at the union of its bulbous and spongy 

 portions. The product of these glands thus would dilute 

 the spermatic fluid, which primarily is quite thick. If a de- 

 cided erection is not followed by the ejaculation of the sperm ; 

 at the cessation of the erection, when the canal returns to its 

 original dimensions, there exudes from its anterior aperture 

 (meatus) a clear and mucous substance, which simply is the 

 secretion from Cowper's glands. 



The other products of secretion, poured into the vacuum 

 formed by the dilatation of the urethral canal, and whose 

 mixture dilutes the sperm and so assists in its easy passage, 

 come from the racemose glands of Littre and the prostatic 

 glands (little glandular pouches radiating from the urethral 

 canal in the posterior half of the prostate (Fig. 131, p. 479) ; 



