Elementary Anatomy of a Hound 51 



hilar. This is the pelvis of the kidney, and it is 

 in this situation that stone or gravel sometimes 

 accumulates, constituting a diseased condition of 

 the worst kind. 



In structure the kidneys are composed of an outer 

 zone known as the cortex, and an inner zone, the 

 medulla, which are formed of numerous tufts of 

 capillaries, called glomeruli, each one a glomerulus ^ 

 and uriniferous tubules lined by epithelial cells. 



The ureters are short tubes entering the bladder 

 at its back part, whilst the urethra (in the male) 

 runs along a grooved bone situated in the substance 

 of the penis, so that it is several inches in length in 

 the male, whereas in the bitch it is short and straight, 

 and has a small opening — with a valve-like arrange- 

 ment — on the floor of the vagina. In the dog it curves 

 around the arch of the pelvic bone and this renders 

 the passage of the sound (catheter) a trifling degree 

 more troublesome; but in both the dog and bitch it is 

 a very simple matter, unless there is some obstruc- 

 tion (such as a stone, etc.) in the passage. 



The bladder has a thick wall and is lined by mucous 

 membrane. It rests when distended on the pubic 

 bone. The neck of this organ is encircled by the 

 prostate gland. 



Muscular contraction forces the urine from the 

 bladder, the acts of urination in the male dog being 

 frequent, and the urine ejaculated spasmodically. 



