48 ON THE MUSCULAR ARRANGEMENTS OE THE BLADDER AND PROSTATE. 
Diagram 9 illustrates the structure of the prostatic portion of the urethra, and the rela- 
tion of the ureters to each other and to the urethra, as seen in the inverted 
bladder. 
a. Longitudinal submucous fibres continued on the urethra. 
b< Ditto, posterior longitudinal fibres. 
c. Slightly oblique spiral fibres curving forward on the urethra. 
g. Ditto, oblique spiral fibres. 
z. Similar fibres from the right ureter. 
v. Very oblique spiral fibres from the left ureter curving round the urethra (7). 
s. The fibres of the right ureter passing across to join with those of the left 
in the mesial line ( b ). 
Diagram 10 shows the conformation of the fundus and the bilateral nature of the 
sphincter in the inverted bladder, the prostatic portion of urethra being 
removed. In this diagram the anterior and posterior sets of fibres only are 
shown. 
a b. Anterior and posterior longitudinal submucous fibres. 
Ill, 1 1 1. Terminal expansions or loops of the very oblique spiral fibres form- 
ing the fourth layer at the fundus posteriorly, and especially concerned 
in the formation of the anterior lip of the sphincter (V). 
yyihyyy • Terminal expansions or loops of the very oblique spiral fibres 
forming the fourth layer at the fundus anteriorly, and especially con- 
cerned in the formation of the posterior lip of the sphincter (ij). 
r and s. Spiral oblique fibres from the right and left ureters (z v), which 
give off filaments to assist in the formation of the sphincter (l 1 y'). 
Diagrams 11, 12, 13, 14, 15, 16, 17, 18, & 19. Accurate outline sketches of transverse 
sections of male prostate and urethra, showing the precise shape and degree 
of obliquity in the urethral canal at different points, and the part which the 
verumontanum plays in the closure of it. (Dissections preserved.) 
a. Urethra at base of prostate, oval in shape, and quite open. 
b. Urethra a little further forward, oval, floor (j) slightly elevated. 
c. Urethra somewhat triangular in shape ; the verumontanum (k) beginning 
to project from the floor or base of the triangle. 
d and e. Urethra more decidedly triangular, the verumontanum (l and m) 
projecting to such an extent as almost to obliterate the urethral canal. 
y*and g. Urethra bayonet-shaped and entirely closed by the projection of the 
Verumontanum ( n , o), which acts at this point as a mechanical wedge. 
h ip g. Urethra circular in form and again becoming patent. 
Diagram 20. Sketch of preparation showing the anterior (l) and posterior (y) lips of the 
sphincter at the cervix. 
