THE CHEST AND ORGANS OF RESPIRATION.          79

droning noise, which may be due either to pleasure or calling the
attention of stragglers to the herd. Again, when being loaded or
driven hard they may roar. This sound is produced by the throat,
the mouth being wide open and the trunk often uplifted. Pleasure
may be indicated by the usual low squeaking through the trunk, as
is often heard when elephants have been separated during the day
and meet in the evening. A further well-known sound is the low
rumbling made in the throat expressive of want or anger; this in a
modified way is often made by calves when separated from their
mothers. The common sound of "prut, prut," which is often heard
when elephants are travelling, I think may indicate impatience.
When elephants desire to frighten anything such as dogs, etc., they
often blow through their trunks.

Vascularity.—This organ is very richly supplied with blood-
vessels, and thus accounts for injuries being attended with copious
haemorrhage, which in fact may prove fatal.

The osseous or bony portion is so constructed as to form two
irregularly shaped chambers communicating in front with the canals
of the trunk, and behind with the mouth. In addition there is free
communication with the honeycomb-like pneumatic chambers (or
air sinuses) of the head already referred to. The chambers are
lined with mucous membrane in which are embedded the terminations
of the olfactory nerves, or nerves of smell, which, being unusually
well developed in the elephant, accounts for the acuteness of this
sense.

Larynx.—This consists of a chamber opening below the base of
the tongue by which air is conducted down the trachea or wind-pipe
into the lungs. It contains the essentials in the production of voice.

Trachea and bronchi.—The trachea or wind-pipe is a tube
composed of a series of cartilaginous rings, which rings are incom-
plete behind. It divides into two tubes of smaller calibre called the
bronchi, which enter the lungs and ramify throughout their sub-
stance. These air passages are unusually long and narrow.

Lungs—Are two spongy organs, one on each side of the chest,
to the walls of which, as already remarked, and to the diaphragm,
they are intimately attached. The left can be readily distinguished
from the right by presenting no deep fissures in its contour.

Healthy lungs are of a delicate pink colour and should float in
water. If however the lungs be not examined till some time after
death, the lung on the side on which the carcass is lying will be
found blackish in colour owing to blood having gravitated into it.

The average weight of the lungs of four animals was 46 lbs.

The mucous membrane at the orifices of the trunk is a rich pink
colour and moist, with an occasional drip of clear fluid. Any