14 



developed excretory ducts to the glandular cavities. Posteriorly 

 one finds centrally a few sinus-like narrow excretory passages, 

 which open into the somewhat larger collecting and excretory duct. 

 The epithelium is of the simple columnar tj-pe and produces a 

 relatively large amount ol' secretion. The gland cavities are sur- 

 rounded by a membrana propria, over which is a relatively thick 

 layer of smooth muscle. Outside this is a connective tissue covering 

 which sends traljeculae or septa in between the lobules. The secre- 

 tion of the seminal vesicles is a tenacious albuminous tliiid with 

 a slightly yellowish tinge, all or part of which appears in the 

 ejaculate in the form of swollen sago-like grains which are soon 

 dissolved following ejaculation and the liquefaction of the semen. 

 The proteid compounds belong to the group of histones. The 

 secretion is liquid when warm and coagulates when cold. Some 

 say that the filling of the vesicles serves to excite sexual feeling, 

 but this is doul)tful in view of the fact that in some animals the 

 sexual desire exists before the vesicles are filled. Likewise, Stein- 

 ach found that rats, whose seminal vesicles had been removed, 

 still retained their desire for copulation. The function of the 

 secretion is to furnish much of the volume to the semen, and in 

 some way it has a distinct 1)earing on fei1:ility, inasmuch as ex- 

 tirpation of the organs in rats leads to lowered fertility. The 

 vesicles of the bull are in no sense a store-house for spermatozoa, 

 as is usually understood. Repeated examinations in a large num- 

 ber of bulls have led to the finding of spermatozoa there only in veiy 

 rare instances. That they serve as a resorption j^lace for sperms 

 that are not ejaculated is also very unlikely. Normally, one sees 

 on smear of the vesicles, occasional cells, leucocytes, lecithin gran- 

 ules, sago bodies, and rarely a few degenerated spermatozoa. 



The CoLLicuLUS Se:mixalis is a rounded or cone-shaped emi- 

 nence in the posterior urethra, upon which the ducts of the sem- 

 inal vesicles and vasa deferentia open. The ducts open separately 

 at the bottom of two narrow slits, one on each side of the mound, 

 there being no distinct ejaculatory duct as in man. The function 

 of the eollicuius or veruinontanum is not definitely known. It 

 is generally believed that the structure is made up of blood spaces 

 which become engorged during erection, causing a l)lockage of 

 the posterior urethi'a. ^»•hich jirevents regurgitation of the semen. 

 Iivtina (27), howcNcr, demonstrated tliat the structure is not com- 

 posed of any unusual number of blood vessels or spaces, and that 

 removal of the organ Avas not followed by regurgitation of the 

 semen into the l)ladder during ejaculation. Tie ])elieves, and quite 

 logically, that its function is to afford a prominence upon which 

 the duets may empty. The mixture of the thick gelatinous semen 

 with the tliin ])rostatic secretion must occur at the moment of 

 ejaculation and must be jierfectly homogeneous, otherwise large 

 num])ers of the organisms remain in the thick gelatinous portion 

 of the fluid. The eminence serves this purpose in that the pros- 

 tatic ducts which converge toward it, may eject their secretion 



