MALE ELEMENTS OF GENERATION. 883 



seminal fluid, as their contents often present a greater or less number of sperm atozoids. 

 Although the mucous membrane of the vesicles seems to produce an independent s. 

 tion, the presence of glands has not been demonstrated. The fact that the fluid capable 

 of fecundating the ovum is produced only by the testicles, that the spermatozoids are 

 the true fecundating elements of the male, and that these are developed in the testicles, 

 shows that the spermatozoids found in the seminal vesicles pass into their cavity from the 

 vasa deferentia. 



The ejaculatory ducts are formed by the union of the vasa deferentia with the ducts 

 of the vesicula3 seminales on either side and open into the prostatic portion of the urethra. 

 Except that their coats are much thinner, they have essentially the same structure as the 

 vasa deferentia. 



Prostate. Surrounding the vesical extremity of the urethra, including what is known 

 as its prostatic portion, is the prostate gland, or body. This organ, except as it secretes 

 a fluid which forms a part of the ejaculated semen, has chiefly a surgical interest, so that 

 it is unnecessary to describe minutely its form and relations. It is enveloped in an 

 exceedingly dense, fibrous coat, contains many glandular structures opening into the 

 urethra, and presents a great number of n on -striated, with a few striated muscular fibres 

 some just beneath the fibrous coat and others penetrating its substance and surrounding 

 the glands. 



The glands of the prostate are most distinct at that portion which lies behind the 

 urethra. In the posterior portion of this canal, are found about twenty openings, which 

 lead to tubes ramifying in the glandular substance. These tubes are formed of a struct- 

 ureless membrane, branching as it penetrates the gland. They present hemispherical 

 diverticula in their course, and terminate in dilated extremities, which are looped and 

 coiled. In the deeper portions of the tubes, the epithelium is columnar or cubical, becom- 

 ing tesselated near their openings, and sometimes laminated. 



The prostatic fluid is probably secreted only at the moment of ejaculation. Its char- 

 acters will be considered under the head of the seminal fluid ; but we may here note 

 that it has been thought by Kraus, that the prostatic fluid has the important function of 

 maintaining the vitality of the spermatozoids. " The spermatozoa, in the absence of the 

 prostatic fluid, cannot live in the mucous membrane of the uterus of mammalia ; but 

 with its aid they may live for a long time in the uterine mucus, often more than thirty- 

 six hours." 



Glands of the Urethra. In front of the prostate, opening into the bulbous portion of 

 the urethra, are two small racemose glands, called the glands of M6ry or of Cowper. 

 These have each a single excretory duct, are lined throughout with cylindrical epithe- 

 lium, and secrete a viscid, mucus-like fluid, which forms a part of the ejaculated scinon. 

 Sometimes there exists only a single gland, and occasionally, though rarely, both are 

 absent. Their function is probably not very important. 



The glands of Littre, found throughout the entire urethra and most abundant on its 

 anterior surface, are simple racemose glands, extending beneath the mucous nuinbrane 

 into the muscular structure, presenting here four or five acini. As these acini are 

 surrounded by muscular fibres, we can readily understand how their secretion \\\^\ 

 pressed out during erection of the penis. They are lined throughout with cc.lmnnar 

 or conoidal epithelium, and secrete a clear and somewhat viscid mucus, which is mixed 

 with the ejaculated semen. 



Male Elements of Generation. 



The ejaculated seminal fluid contains the male elements of generation; hut it 

 be remembered that the complex fluid known as the semen is composed of anat< 

 elements developed in the testicle itself, mixed with the secretion of the r*M d, :, ; vntia, 



