n Lower Egypt,
where it was called the river hog, but at the present day it is
necessary to go a good distance south of Nubia in order to find it. In
many rivers it migrates with the seasons. It descends the river as this
falls in the dry season, and moves up again when the bed is filled by
rain.

The body of the hippopotamus is round and clumsy, and is supported by
four short shapeless legs with four hoofed toes on each foot. The
singular head is nearly quadrangular, the eyes and ears are small, the
snout enormously broad and the nostrils wide (Plate XXIX.). The hairless
hide, three-quarters of an inch thick, changes from grey to dark brown
and dirty red according as it is dry or wet. The animal is thirteen feet
long, without the small short tail, and weighs as much as thirty
full-grown men.

The hippopotamus spends most of his time in the water, but goes on land
at night, especially in those districts where the rivers do not afford
much food. Stealing carefully along a quiet river the traveller may
often take him by surprise, and see two small jets of water rise from
his nostrils when he comes up to breathe, snorting and puffing noisily.
Then he dives again, and can remain under water three or four minutes.
When he lies near the surface only six small knobs are seen above the
water, the ears, eyes, and nostrils. If he is not quite sure of the
neighbourhood, he thrusts only his nostrils above water and breathes as
noiselessly as possible.

Hippopotami often lie splashing in shallow water, or climb up on to the
bank to sun themselves and have a quiet lazy time. Very frequently they
are heard to make a grunting noise of satisfaction. When evening comes
they seek the deeper parts of the river, where they swim up and down,
chase one another, and roll about in the water with great nimbleness and
activity. They swim with great speed, throwing themselves forward in
jerks, and filling the air with their gurgling bellowing cry; yet if
they like they can swim so quietly that not the least ripple is heard. A
wounded hippopotamus stirs up the water so that a small canoe may
capsize in the swell from his forequarters.

When several old males are bellowing together, the din is heard for
miles through the forest and rolls like thunder over the water. No other
animal can make such a noise. Even the lion stops to listen.

On the Upper Nile, above Khartum, where the most luxuriant vegetation
struggles for room on the banks, and th