3H-4 MR. F. E. BEDDARD ON THE [Apr- ^ 9j 



gated, highly granular cells ; the ret of the epithelium of the gland 

 is comp'.ised of glandular cells, rounded and swollen at the ba>e 

 and terminating in a fine slender duct; there are numerous iovns 

 of thee cells. The lumen ot the gland for the posterior half is 

 triangular (Plate XXXIII. fig. 8) ; further forward (fig. 9) it 

 becomes cros^-shaped. In the posterior half of the prostate, how- 

 ever, the gland is di^-ided into two tubes, which are quite independent 

 of each other : rather behind the point at which the vasa deferentia 

 perforate the coats of the prostate the inner circular muscular layer 

 of the gland is deflected inwards (see fig. 1 0), and cuts up the inte- 

 rior into two parallel chambers ; the one contains the continuation 

 of the lumen of the prostate which has just been described, while 

 the other contains at first merely a ma?s of glandular cells cut off 

 from the outer layers of glandular epithelium by the invasion of the 

 circular muscular layer. Presently a lumen is developed in this part 

 of the gland, which has a cre^centic outline ; there is absolutely no 

 continuity at this end between the two tubes ; the lining epithelium 

 of the second tube ultimately comes to resemble in every particular 

 that of the principal tube ; there is no external indication of the 

 division of the prostate into two parallel tubes ; the section of the 

 whole organ is an unbroken ellipse. Where the vasa deferentia 

 perforate the walls of the prostate the second tui.e is already estab- 

 lished ; the vasa deferentia make their way sepaiately through the 

 muscular coats of the gland, losing their own special muscles : the 

 vasa deferentia become very fine tubes, which are not easy to recog- 

 nize ; they appear to become uiuted in the circular muscular coat of 

 the prostate into a single tube which passes along the muscles 

 dividing up the interior of the prostate ; the vas deferens then 

 becomes continuous with the prostate gland, but with the original 

 portion of the gland, and not with the second tube. Theoretically 

 one might suppose that each vas deferens opened into a separate 

 part of the prostate, and that the division of the latter corresponded 

 to the separation of the vasa deferentia ; I cannot, however, find any 

 evidence that this is the case. 



Each of the two portions of the prostate becomes continuous with 

 a narrow tube that leads to the penis (see fig. 15) ; in correspondence 

 with the diiference in size between the two portions of the prostate, 

 the outermost of the two tubes leading to the penis is smaller than 

 the inner. A little before they enter the penis the two tubes join 

 into a single tube. 



'I'he penis (p, Plate XXXIII. fig. 1.5) is a muscular process of the 

 walls of the bursa copulatrix ; it contains a median canal, which is 

 continuous with the lumen of the duct of the prostate gland. The 

 internal canal of the penis, however, does not alone communicate with 

 the vas deferens ; towards the base of the organ, i. e. towards its base 

 of attachment to the walls of the bursa, it bears a longituchnal groove, 

 which shortly becomes closed in and forms a canal, ultimately 

 opening into the canal of the penis ; tbere is therefore an open com- 

 munication between the vas deferens and the interior of the bursa 

 copulatrix ; in fact, in the specimen which I studied by means of 

 transverse section*, a mass of spermatozoa partly filled up the canal 



