OF THE BLADDER AND PROSTATE. 
37 
uretral orifices. The ureters, however, as the reader is aware, are in reality situated 
within the walls of the bladder, and are grasped alike by the external and internal 
fibres (Plate V. figs. 14 & 17, 2 , 2 ), an arrangement which dispenses with the necessity 
for special muscles. What therefore was delegated to separate structures is more 
conveniently and effectively performed by the fibres of the bladder itself. 
The longitudinal and oblique fibres occurring between the muscles of Bell, and which 
enter principally into the formatian of the uvula and median ridge of the female and 
the verumontanum of the male, are continued forwards on the urethra of the latter. 
They are variously disposed. At the apex of the prostate they diverge and bifurcate to 
a greater or less degree. On the membranous portion of the canal some are oblique 
and some straight. Further forwards they diverge and then converge to form an oval 
patch corresponding to the posterior third of the spongy portion ; they subsequently 
diverge in the direction of the glans penis, where they spread out to embrace the fossa 
navicularis. Here they apparently terminate in loops. 
RECAPITULATION. 
The points which I have sought more especially to establish in the present memoir 
are the following : — 
I have endeavoured to show that the fibres of the bladder are spiral continuous fibres 
arranged for the most part in the form of figure-of-eight loops, the loops being directed 
towards and embracing the urachus and urethra respectively. 
The fibres distribute themselves on the anterior, posterior, and lateral surfaces, and 
are divisible into seven layers or strata, which are more or less perfect, viz. three external, 
a fourth or central, and three internal. The fibres of the first and seventh layers (the 
most external and most internal) pursue a nearly vertical direction and are feebly deve- 
loped ; the fibres of the second and sixth layers, which are stronger and occupy a deeper 
situation, running in a slightly oblique spiral direction and crossing at acute angles ; 
those of the third and fifth layers, which are still stronger and deeper than any of the 
others, running in a spiral oblique direction and crossing at obtuse angles. The fibres 
of the fourth or central layer pursue a very oblique spiral course, and cross at such 
obtuse angles as to have been up till the present regarded as circular fibres. The fibres in 
this manner increase in strength and in obliquity, both from without and from within, and 
form by their interlacings a structure remarkable alike for its complexity and its beauty. 
The apex and base are structurally identical, and consist of longitudinal, slightly ob- 
lique, oblique, and very oblique or circular external and internal fibres, crossing and 
interlacing as in the other portions of the vesical parietes. 
The longitudinal or vertical fibres have a crucial arrangement at the apex and base, 
and the slightly oblique ones are drawn together at the urachus and cervix by the con- 
strictions which in the embryo separate the bladder from the allantois and ureth’ a„ 
This stellate arrangement occasions a thickening of the walls of the bladder at the points 
indicated, and renders the bladder impervious in both directions; the urethra, unless 
