Face, ears, naked parts of hands and feet, black; upper eyelids white; fur of head, back, and limbs in general brownish-yellow—the hairs being ringed with alternate bars of black and light-brown; cheeks and whiskers fawn-coloured; throat and under side of body paler. Scrotum, callosities, and naked parts of buttocks bright flesh-coloured, but not so bright as in C. hamadryas. Length of body (in young male), 27 inches; of tail, 20 inches.
Female and Young Male.—Similar to adult males in coloration; but less thick-set, and with a shorter muzzle.
Distribution.—The Guinea Baboon inhabits West Africa from Senegal and the Niger to Central Africa. In East Africa, Mr. H. H. Johnston observed it in the inhabited region of Kilimanjaro.
Habits.—Little is known of the habits of this species; but it is improbable that it departs widely from those of the other members of the genus. In regard to the bright coloration of the callosities and posterior parts of this and other Baboons, Mr. Darwin remarks: "In the discussion on sexual selection in my 'Descent of Man,' no case interested and perplexed me so much as the highly-coloured hinder ends and adjoining parts of certain Monkeys. As these parts are more brightly coloured in one sex than the other, and as they become more brilliant during the season of love, I concluded that the colours had been gained as a sexual attraction.... I had, however, at that time no evidence of Monkeys exhibiting this part of their bodies during their courtship.... I have lately read [in an article by J. von Fischer, of Gotha, published in April, 1876] an account of the behaviour of a young male Mandrill when he first beheld himself in a looking-glass, and it is added, that after a time he turned round and presented his red hinder end to the glass. Accordingly I wrote to Herr J. von Fischer to ask what he supposed was the meaning of this strange action. He says that he was himself at first perplexed ... and was thus led carefully to observe several individuals of various other species of Monkeys, which he has long kept in his house. He finds that not only the Mandrill (C. mormon) but the Drill (C. leucophæus) and three other kinds of Baboons (C. hamadryas, C. sphinx, and C. babuin) ... turn this part of their bodies, which in all these species is more or less brightly coloured, to him when they are pleased, and to other persons as a sort of greeting.... From these facts von Fischer concludes that the Monkeys which behaved in this manner before a looking-glass ... acted as if their reflection were a new acquaintance.... It deserves especial attention that von Fischer has never seen any species purposely exhibit the hinder part of its body, if not at all coloured.... With respect to the origin of the habit, it seems to me probable that the bright colours, whether on the face or hinder end, or as in the Mandrill, on both, serve as a sexual ornament and attraction.... The fact that it is only the Monkeys (with those parts brightly coloured), which as far as at present known, act in this manner as a greeting towards other Monkeys, renders it doubtful whether the habit was first acquired from some independent cause, and that afterwards the parts in question were coloured as a sexual ornament; or whether the colouring and the habit of turning round were first acquired through variation and sexual selection, and that afterwards the habit was retained as a sign of pleasure, or as a greeting, through the principle of inherited association."
X. THE ARABIAN BABOON. PAPIO HAMADRYAS.
Simia hamadryas, Linn., Syst. Nat., i., p. 36 (1766).
Le tartarin, F. Cuvier and Geoffr., Mamm., vol. i., livr. 5 (1819).
Cynocephalus hamadryas, Fr. Cuvier, Hist. Nat. Mammif., p. 129, pl. 46 (♂).
Papio hamadryas, Geoffr., Ann. Mus., xix., p. 103 (1812); Schl., Mus. Pays Bas, vii., p. 129 (1876, in part).
Hamadryas ægyptiaca, Gray, Cat. Monkeys Brit. Mus., p. 34 (1870).