68 
THE VETERINARY SCJEKrP. 
cavity lining the bowels. The inside is Hned with mucous 
membrane which is thrown into folds when the bladder is 
empty. Another coat is found, between the two membranes 
above mentioned, called the muscular coat, the action of 
which is to contract the bladder when the animal wants 
to urinate. The bladder is held in place by ligaments. 
The rectum lies above the' bladder, which in the horse rests 
on the floor of the pelvic cavity. Its position in the mare 
differs from that of the horse. Instead of the rectum or back 
bowel being immediately above it, as in the horse, the womb 
is just above the bladder or between it and the rectum. The 
bladder acts as a reservoir in which to store the water until it 
is full; it then presses on the walls and nerves, giving a 
peculiar sensation to these parts, causing the walls to con- 
tract, forcing the water into a tube which carries it from the 
body. This tube is called the urethra. The neck of the 
bladder is simply an opening at the back part, and is guarded 
by a valve which prevents the urine from dripping out except 
when the animal is passing its water. 
4. The Urethra is the tube which carries the water from 
the bladder out of the body. It is situated much differently 
in the mare than in the horse. In the mare it is very short, 
passing from the neck of the bladder along below the womb 
and vagina, which is the passage from the outside into the 
neck of the womb. It opens up into the underside of this 
passage about four inches in from the outside. This opening 
is guarded by a small thin valve, and can be felt by passing 
the finger along the under side of the passage which leads 
into the womb. In the horse this tube is a great deal longer 
than in the mare. It commences at the bladder, passes along 
below the rectum or back bowel to just below the anus 
Here this tube bends downward and forward and passes into 
the penis, continuing down to the end, where it terminates. 
Its purpose is to carry the urine from the bladder out of the 
body and to perform certain duties in connection with the 
genital organs. Its lining is a continuation of the membrane 
of the bladder. 
