15 



toward the eminence, producing an admixture more evenly and 

 quickly. 



Prostate: The hull possesses -what Ellenherger calls a diffuse 

 prostate. That is, there is no distinct glandular hody as in man. 

 It is composed principally of a glandular sheath around the 

 urethral wall. Just posterior to the neck of the bladder, and in 

 front of the urethral muscle, there is formed a slight dorsal trans- 

 verse elevation, extending downward on the sides. This is what 

 might be termed the body. The greater part of the gland is 

 "disseminate" in form, being a sheath of glandular tissue em- 

 bedded in the urethral wall. Dorsally it is about ten to twelve 

 millimeters thick, and ventrally about two millimeters. The gland 

 is a branched tul)ular structure, the interlobular tissue of which 

 contains much unstriped muscle. The lobules arc lined by a 

 columnar type of epithelium. The ducts, about thirty to forty 

 in numl)er, o])en into the urethra in two rows posterior to the 

 colliculus. The secretion is a thin, slightly turbid fluid, of a 

 faintly alkaline reaction. Its function is to dilute the semen, 

 stimulate the motility of the spermatozoa and nourish them. 



Fish (28) believes that the activating property of the secretion 

 is due to enzymes, because boiling deprives the fluid of its power 

 to accelerate the motility of the spermatozoa. Serrlach and Pares, 

 quoted by ]\rarshall (29), working on dogs, have adduced evidence 

 indicating that the prostate is an internal secretory gland which 

 controls the testicular functions, and regulates the process of 

 ejaculation. It is stated that if the prostate is removed, sperma- 

 tozoa are no longer produced in the testis, and that the secretory 

 activity of the accessory genital glands ceases. These changes, 

 however, 'can be prevented by the administration of extracts of 

 the prostate. The fact that the prostate elaborates a secretion 

 having a definite relation to the testis, has been verified by other 

 authors. 



Cowper's Geaxds (Bull)o-Urethral) : These glands are paired, 

 oval structures about one and one-half by two and one-half centi- 

 meters in size, situated on either side of the dorsal pelvic part of 

 the urethra close to the ischial arch. They are deeply embedded, 

 with the bull)us urethae, in the bulbo-cavernosus muscle, thereby 

 being inaccessil)le to palpation. Tn general, they are of a well 

 developed anastomosing tubular type. The connective tissue 

 .stroma is relatively thin, and thickens only in between the larger 

 lobules, where one finds the larger collecting ducts. Each gland 

 opens by a single duct. The epithelium is of the sim])le cuboidal 

 type, ijittle is known of the function of its .secretion, though 

 Kingsbury '':"50^ regards it in the light of a mating gland; that is. 

 it lubricates the genital passages dui-ing coitus, as does its 

 homologous structure in the female, Bartholin's gland. 



Ellenberger describes the urethra, .slit ventrally, as presenting 

 the following picture: "The colliculus seminalis distinctly ap- 



