104 THE VOYAGE OF H.M.S. CHALLENGER. 



organ presents a uniform medullary substance coated by a thin layer of cortical substance. 

 The uriniferous tubules open upon the surface of a single prominent papilla which projects 

 into the pelvis of the kidney. The ureters where they are attached to the kidneys show 

 only a very slight expansion. 



The bladder (fig. 6, b., and fig. 7, c.) was in a contracted state, and was remarkable 

 for its small size ; indeed it was not larger than a small walnut. In shape it is ovoid — 

 compressed from before backwards — and its walls are exceedingly thick and muscular. It 

 is completely invested by peritoneum, and connected by a distinct fold or mesentery to 

 the upper aspect of the lower abdominal wall. No trace of a urachus could be detected. 

 In front the muscular fibres are disposed in strongly-marked transverse columns which are 

 separated from each other by intervening fissures ; laterally, they have a longitudinal 

 direction, whilst behind, they run in the form of oblique bundles with furrows between 

 them. The neck of the bladder abuts against the broad anterior end of the prostate, and 

 its walls are much thinner than those of the body of the viscus. 



The ureters (fig. 6, a) pierce the inner aspect of the neck of the bladder, one on 

 each side of the mesial plane and about a quarter of an inch apart. Immediately behind 

 these the vasa deferentia (fig. 6, c) pierce the commencement of the urethra. 



The mucous membrane lining the bladder in its contracted state is very rugose, more 

 especially towards the summit. Near the neck of the organ the rugosity becomes less 

 marked, and where the neck merges into the urethra it is perfectly smooth. 



The ureters pursue a curious course through the vesical wall ; at first directed back- 

 wards for a distance of about a quarter of an inch they then bend suddenly forwards and 

 increase in calibre. Each duct opens upon a prominent papilla situated at the neck of 

 the bladder. 



Testicles and vasa deferentia. — The body of the testicle is small and spherical, not 

 more than half an inch in diameter. The epididymis on the other hand is exceed- 

 ingly large, and so long that it surrounds the body of the testicle for fully three-fourths 

 of its circumference. The vas deferens is a slender uniform tube — 7^ inches in length. 

 It shows no tendency to dilatation or sacculation as it approaches the neck of the bladder, 

 and it has no diverticulum or seminal vesicle in connection with it. It sinks into the 

 urethral wall, close to the base of the prostate, and immediately behind the point where 

 the ureter disappears into the vesical wall. 



Prostate, (fig. 6, m, fig. 7, d). The prostate is a large pyriform body, possessing a 

 shape very similar to that of a carrot. It commences at the neck of the bladder by a 

 broad base, and it gradually tapers away as it is traced towards the outlet of the pelvis 

 until it is finally lost upon the urethra, In length it measured four and a half inches, 

 whilst its base or broadest part had a diameter of three quarters of an inch. The urethra 

 traverses its entire length and its surface is smooth and uniform, with no external marking 

 or furrow of any kind indicative of a lobular constitution. 



