G74 



ANATOMY OF VERTEBRATES. 



531 



v 



ing from -gfa to -^-^ of an inch in length. They are conveyed, 

 with the fluid in which they move, by the spermducts to the 

 beginning of the urethra. The ducts are slightly enlarged, chiefly 



through thickening of their walls, 

 near their termination, fig. 531, f } 

 as they pass along the inner sides 

 of the vesicular glands, v ; they 

 again contract to communicate, each 



with the duct of the ffland of its 



~ 



own side, at d. The vesicular gland 

 is a fusiform multilocular bag about 

 two inches in length and three 

 quarters of an inch in greatest 

 breadth. The lower attenuated end 

 penetrates the prostate between the 

 lateral, p, and medial, c, lobes, and 

 after joining the vas deferens, the 

 common duct terminates at the side 

 of the urethral depression called 

 6 sinus pocularis,' fig. 532,^,^. Each 

 1 vesicula ' is invested by a fascia, 

 011 removal of which, with some 

 maceration and dissection, it is 

 shown to consist of a main tube 

 with, commonly, three or four ca3cal 

 diverticular appendages. This tube 

 has a much smaller calibre for a 

 short distance from its junction with the vas deferens than else- 

 where. The narrow portion is straight, and is commonly called 

 the duct. The vesicular glands are found to contain a glairy 

 mucus, deepening to a brownish colour soon after death, and 

 containing stray spermatozoa. The prostate, figs. 531, 533, p, 

 is a more compact glandular body surrounding the neck of the 

 bladder and beginning of the urethra, deriving its name from 

 its position in front of the vesicular glands. It is surrounded 

 by a dense fascia, which adheres firmly to the glandular sub- 

 stance. This is of a lightish brown colour, and very firm texture. 

 It forms two lateral lobes, of an ovoid shape, between which 

 is a small middle lobe. It is composed of minute canals with 

 blind follicular beginnings, which unite together to form ducts, 

 opening in an oblique manner on the prostatic portion of the 

 urethra. Their orifices are situated around the most elevated 

 portion of the verumontanum, in the form of a crescent, fig. 

 532, e. The depression, or ' sinus,' in front of this valvular 



A posterior view of the human bladder 

 and prostate : tlie spermducts and ve- 

 sicular are reflected downward; half 

 natural size, xxviu. 



