MUCOUS AND SEROUS MEMBRANES.             75

It is furnished with blood vessels, nerves, etc. In health it is-
of a delicate pink colour ; in fever and inflammations it becomes,
reddish, and the minute blood vessels are frequently injected ; when,
the liver is deranged they assume a yellowish tint; and in debility
and anæmia the membrane is usually pale and bloodless. In the
elephant the colour of the mucous membrane covering the mouth,
tongue and palate is easy to note ; sometimes that covering the
eye can also be seen, and this latter being of a highly delicate-
structure shows any changes in a marked manner.

                         SEROUS MEMBRANE

Is a firm white membrane lining the closed cavities of the body,
i.e., those not communicating with the external air. The membrane
is reflected over the organs contained within these cavities. Its
duty being to protect and keep them in position also by means of a
very small quantity of lubricant fluid (serous fluid) which it secretes,
it permits the organs to glide freely over each other without injury.
In particular positions the membrane receives distinctive names:
that portion lining the thorax is called the pleura ; that lining the
abdominal cavity, the peritoneum ; while the portion which suspends
the bowel is known as the mesentery. In the elephant the peri-
toneum is very thick, and there is a general absence of fat which
is usually to be found in most animals.

                         MUSCULAR SYSTEM.

This system is remarkable, in that a large amount of tendinous
fibre runs through the muscles, making them very tough. About
the shoulders and buttocks the muscles are fleshy, but even here
there is a considerable admixture of tendinous fibre. The flesh is
much relished by Burmans, Shans and Karens.