When angry their jaws are moved up and down with great rapidity, while they give utterance to loud and harsh cries. The males fight with their strong canine teeth and their long and strong, though flat, nails, with which they are capable of inflicting deep wounds on each other. When in a good temper their voice is generally soft; but Mr. Darwin observed in the Zoological Gardens that a specimen there, when pleased, made a shrill note, and likewise drew back the corners of its mouth, apparently through the contraction of the same muscles as with human beings. The skin of the lower eyelids also became much wrinkled. "At the same time it rapidly moved its lower jaw or lips in a spasmodic manner, the teeth being exposed; but the noise produced was hardly more distinct than that which we call silent laughter. Two of the keepers affirmed that this {8}slight sound was the animal's laughter, and when I expressed some doubt on this head (being at the time quite inexperienced) they made it attack, or rather threaten, a hated _Entellus_ Monkey, living in the same compartment. Instantly the whole expression of the face of the _Inuus_ changed; the mouth was opened much more widely, the canine teeth were more fully exposed, and a hoarse barking noise was uttered." II. THE BROWN MACAQUE. MACACUS ARCTOIDES. _Macacus speciosus_, F. Cuvier, Mamm., pl. xlvi. (Feb., 1825) (founded on a drawing). _Macacus arctoides_, Is. Geoffr., Mag. de Zool., 1833, p. cli., pl. ii.; Sclater, P. Z. S., 1872, p. 203; Anderson, Zool. Yun-nan, p. 45, pls. i. and ii. (1878) with full synonymy; Blanford, Faun. Brit. Ind., Mamm., p. 17 (1891); Schl., Mus. Pays-Bas, viii., p. 116 (1876). _Papio melanotus_, Ogilby, P. Z. S., 1839, p. 31. _Macacus melanotus_, Gray, Cat. Monkeys Brit. Mus., p. 29 (1870). _Macacus thibetanus_, Alph., Milne-Edwards, C. R., lxx., p. 341 (1870). _Macacus brunneus_, Anderson, P. Z. S., 1871, p. 628, 1872, p. 203, pl. xii. (Jun.), 1874, p. 652. CHARACTERS.--Body short and stout; head large; muzzle short and truncated; chin bulging; chin and throat almost nude; eyes large; ears large and rounded, with a pointed projection behind; limbs short, stout and strong; hands and fingers short, the terminal phalanges nude; tail almost rudimentary; callosities and surrounding region of buttocks naked. Fur long and woolly (especially in those living at high {9}altitudes), longer on the head, back and limbs, shortest over the sacrum; hair on the head parted outwards from the centre; fingers slightly haired; tail thinly haired, or nude in old animals. In individuals living in the inclement regions of Eastern Thibet, the tail is thickly haired.