an uncertain extent of Hindostan, on the main land of Asia.
The largest attain a few inches above three feet in height, from the
crown to the heel, so that they are shorter than the other man-like
Apes; while the slenderness of their bodies renders their mass far
smaller in proportion even to this diminished height.

Dr. Salomon Muller, an accomplished Dutch naturalist, who lived for many
years in the Eastern Archipelago, and to the results of whose personal
experience I shall frequently have occasion to refer, states that the
Gibbons are true mountaineers, loving the slopes and edges of the hills,
though they rarely ascend beyond the limit of the fig-trees. All day
long they haunt the tops of the tall trees; and though, towards evening,
they descend in small troops to the open ground, no sooner do they spy
a man than they dart up the hill-sides, and disappear in the darker
valleys.

All observers testify to the prodigious volume of voice possessed by
these animals. According to the writer whom I have just cited, in one of
them, the Siamang, "the voice is grave and penetrating, resembling the
sounds goek, goek, goek, goek, goek ha ha ha ha haaaaa, and may easily
be heard at a distance of half a league." While the cry is being
uttered, the great membranous bag under the throat which communicates
with the organ of voice, the so-called "laryngeal sac," becomes greatly
distended, diminishing again when the creature relapses into silence.

M. Duvaucel, likewise, affirms that the cry of the Siamang may be heard
for miles--making the woods ring again. So Mr. Martin* describes the cry
of the agile Gibbon as "overpowering and deafening" in a room, and "from
its strength, well calculated for resounding through the vast forests."
([Footnote] *'Man and Monkies', p. 423.) Mr. Waterhouse, an accomplished
musician as well as zoologist, says, "The Gibbon's voice is certainly
much more powerful than that of any singer I have ever heard." And yet
it is to be recollected that this animal is not half the height of, and
far less bulky in proportion than, a man.

There is good testimony that various species of Gibbon readily take to
the erect posture. Mr. George Bennett,* a very excellent observer, in
describing the habits of a male 'Hylobates syndactylus' which remained
for some time in his possession, says: "He invariably walks in the erect
posture when on a level surface; and then the arms either hang down,
enabling him to assist hims