332 GENERATION. 



plete and normal intercourse, when both, the male and fe- 

 male participate, more or less, in the sexual act. 



Action of the Male. The act of sexual intercourse is pre- 

 ceded, in the male, by a longer or shorter period of excite- 

 ment, the most important manifestation of which is erection 

 and rigidity of the penis. This is largely controlled by the 

 nervous system. It may be due to distention of the vesiculae 

 seminales, and, perhaps, of the tubes of the testicle and epi- 

 didymis after prolonged continence, to the imagination, or 

 to the presence or thought of a female exciting desire. The 

 excitement may, also, be arrested by a sudden feeling of dis- 

 gust, modesty, or fear ; and it sometimes happens that the 

 excitement is so intense that the male organ becomes flaccid 

 without ejaculation. An occurrence of this kind frequently 

 occasions such an amount of mortification and apprehension 

 for the future, that, from the mere dread of a similar acci- 

 dent, there is frequently an incapacity for intercourse when, 

 in all other respects, the conditions are absolutely normal. 

 Physicians have frequent occasion to observe this, especially 

 in the newly-married, who are often afflicted with the fear of 

 permanent sexual incapacity, and seek professional advice. 

 This illustrates the influence of the nervous system upon the 

 sexual organs, in the absence of diseased conditions. 



Unlike certain of the lower animals, the human subject 

 presents no distinct periodicity in the development of the 

 spermatozoids ; but, in reiterated connection, an excitement 

 and orgasm may occur when the ejaculated fluid has no fe- 

 cundating properties. Such frequently-repeated sexual acts 

 are abnormal ; but, from a purely physiological point of 

 view, prolonged continence is equally unnatural and may 

 react unfavorably on the nervous system. No absolute or 

 even approximative rule can be laid down with regard to the 

 frequency with which intercourse may take place within 

 physiological limits. "We may assume that these conditions 

 are fulfilled, first, when intercourse is confined within the 



