Part 3

HABITS.--The Aye-Aye, whose name is derived from its call of "hai-hay," is one of the most singular of living animals. It was first discovered by Sonnerat during his travels in {17}Madagascar in 1780, and by him sent to Paris. The skin remained unique in Europe for the best part of a century. Greatly owing to the superstitious dread in which the creature is held by the natives, it was for a long period, and is still, very difficult to procure, or to induce the natives to capture, specimens. Mr. Baron says that it is sometimes accidentally caught in traps by the natives, "but the owner of the trap, unless one of those versed in the Aye-Aye mysteries who know the charm by which to counteract its evil power, smears fat over it, thus securing its forgiveness and goodwill, and sets it free." In 1863 Dr. Sandwith sent a second example to Europe, the anatomy of whose body was made the subject of an exhaustive monograph by the late Sir Richard Owen. Since that date more than one specimen has been received alive, and its habits and constitution are now fairly well known. The Aye-Aye is entirely arboreal and nocturnal, sleeping during the day, with its body coiled round, lying on its side with its bushy tail spread over it as a covering. It suspends itself by its hind-limbs, and in this position it has been observed in captivity by Mr. Bartlett, using its hook-like finger to comb out its tail, to cleanse its face, the corners of its eyes, its nose, mouth, and ears, keeping meanwhile its other fingers closed. It lives in the depths of the forests, going about in pairs. Exquisitely keen of hearing, it can detect by sound the boring of insects within the dead branches of trees. Its attenuated wire-like finger acts as a probe to discover their position, and its powerful incisor teeth are used to cut down upon the tunnel of its prey, which consists principally of the Andraitra, the larva of a Beetle, which it then extracts with the same digit. The juices of plants are also supposed to form part of its food. It drinks after the manner of many Monkeys, by dipping its fingers into the water, and {18}drawing them through its mouth. The Aye-Aye is fearless of Man, but in its wakeful hours, during the night, when irritated it can be very savage and strike out with its hands. The female produces but one young at a birth, and builds, in the fork of a tree, a ball-like nest, two feet in diameter, with an entrance hole in the side, forming it of the rolled up leaves of the Travellers'-tree, and lining it with small twigs and dry leaves. (_Baron._)

THE TARSIERS. FAMILY TARSIIDÆ.

This family, like the preceding, has been constituted for the reception of two animals which are so remarkably distinct from all the other species of Lemurs, as to necessitate their being thus segregated. Between these two forms however, so close a relationship exists, that they have often been considered as only varieties of the same species. The family, therefore, consists, as in the _Chiromyidæ_, of a single genus, the characters of which constitute also those of the family.

THE TARSIERS. GENUS TARSIUS.

_Tarsius_, Storr. Prod. Method. Mamm., p. 32 (1780).

The Tarsiers are distinguished externally by the possession of a rounded head, and a very short, pointed muzzle; by their very large, long and naked ears, and eyes so remarkably large and protruding, as to form the most prominent feature of the face. The hind-limb, which is much longer than the fore-limb, is also very remarkable on account of the great elongation of the ankle-region (or tarsus) of the limb. The long and slender toes terminate in round, sucker-like discs, and are furnished with flat nails, except on the second and third toes, where the nails are merely compressed claws. The {19}fore-limb, with or without the hand, is longer than the trunk; its digits also are long and slender (the third being longest, and the second equal to the fourth) and, like those of the foot, terminate in round sucker-like discs. Both the wrist and ankle are haired.

The long and Rat-like tail is longer than the body, and has a tufted termination. The skull presents enormous eye-cavities, the inner margins of the latter almost meeting in the centre. The orbits are nearly closed in from the temporal fossa by the union of the malar and alisphenoid bones--a character in which they differ from all other Lemurs, and approach the Anthropoid section of the Primates. Their dental formula is I2/1, C1/1, P3/3, M3/3 = 34. Of the upper jaw, the incisors are prominent and unequal, the anterior ones being larger than the posterior, and in contact in the middle line, thus leaving no central gap in the front of the jaw, as is the rule among Lemurs; the canines are about as long vertically as the inner incisor, and are smaller than the corresponding tooth in the True Lemurs; the pre-molars are canine-like, sharp, pointed, and furnished with a cingulum; the anterior pre-molar is smaller than the two others; the posterior pre-molar has one external and one internal cusp; the molars, all nearly equal in size, are wide transversely, strongly cingulate, and have two prominent external cusps. In the lower jaw, the solitary incisor in each half is small, and, instead of protruding horizontally, is nearly erect; the canines are also almost erect, and less like incisors than is usual in the Sub-order. The pre-molars are sharp, but the anterior is smaller than the two posterior; the anterior and median molars have four cusps, and are cingulate, while the posterior molar has five cusps.

{20}The Tarsiers have nineteen dorsal and lumbar vertebræ together, and twenty-seven in the tail. The humerus presents a perforation (the entepicondylar foramen) at its lower inner side, and another nearly in the centre above the hinge. The femur is more than twice the length of the arm-bone; the lower half of the slender fibula is co-ossified with the tibia, while two of the tarsal, or ankle-bones (the _calcaneum_ and _naviculare_), are remarkably elongated, thus giving to the hind-limb of these animals the singular conformation from which they derive their name. The large intestine is not convoluted upon itself as in so many of the Lemurs, nor is there a cæcum at the junction of its smaller and larger portions.

I. THE SPECTRAL TARSIER. TARSIUS TARSIUS.

_Lemur tarsius_, Erxl., Syst. Regn. Anim., Mamm., p. 71 (1777).

_Tarsius spectrum_, Geoffr., Ann. Mus., xix., p. 168 (1812); Dahlb., Studia, p. 231, tab. 11.

_Lemur spectrum_, Pallas, Nova Sp. Glir. Ord., p. 275, note (1778).

(_Plate II._)

CHARACTERS.--On the upper lip, sides of nostrils, and over the eyes long, delicate black hairs (_vibrissæ_); hair on nose very short, longer in front of ears and at angles of mouth. Fur of body generally thick, woolly, the basal two thirds slate-grey, the terminal third brownish-yellow. Face to forehead fawn-brown, somewhat darker around and between the enormous liquid brown eyes. Top and back of head and shoulders of a more uniform and darker shade; rest of back apparently mottled, owing to the light-tipped hairs of that region gathering into locks. Under side of body, inside of arms and legs paler. Tail darker brown, rufous at base of upper side. Size not exceeding that of a small Rat.

PLATE II.

{21}DISTRIBUTION.--Found only in the jungles of the Malayan islands of Sumatra, Java, Banka, Billiton, and Borneo.

II. THE DUSKY-HANDED TARSIER. TARSIUS FUSCUS.

_? Lemur podje_, Kerr, Linn. Anim. Kingdom, p. 86 (1792).

_Tarsius fuscus, s. fuscomanus_, Fischer, Anat. der Maki, pp. 3, 7 (1784).

_Tarsius fuscomanus_, Geoffr., Ann. Mus., xix., p. 168 (1812); Max Weber, Zool. Ergebn. Reis. Nederl. Ost-Indien, iii., p. 264 (1893).

_Tarsius fischeri_, Burm. Tarsius, pp. 29, 129 (1846).

CHARACTERS.--Closely related to the preceding species in size and other characters, but distinguished by the colour of the hands, which are dark brown.

DISTRIBUTION.--Inhabits the islands of the Indian Archipelago, farther to the eastward than those in which _Tarsius Tarsius_ is found. It has been recorded from Celebes, and the neighbouring groups of Salayer and Sanghir, and from some of the Philippine Islands, such as Bohol and Mindanao.

HABITS.--The habits of both species of Tarsier are identical, and may be described together. They are almost entirely nocturnal and arboreal animals, rarely, of their own accord, coming to the ground. They move from place to place by leaping along the larger branches, or from tree to tree, even when these stand several feet distant. When they do descend, however, they advance on the ground by the same curious Frog-like leaps, without bringing their fore-limbs down to the ground. The Tarsier is said to climb easily, even without grasping, by means of the round discs on its slender finger-tips, which, like suckers, enable it to hold on by the side pressure of its limbs to any smooth surface, such as the stems of the {22}bamboo-brakes which it frequents. Mr. Charles Hose, in his "Mammals of Borneo," states that, in that island, the Tarsier is found in the jungles of the low country, skipping about from branch to branch. According to the notes of this excellent field-naturalist, it has a habit of turning its head almost completely round without moving the rest of its body. This very remarkable creature lives in pairs in the tropical forests, in holes in the tree stems, or under their roots, feeding chiefly on insects and small lizards, which, as Mr. Cuming has recorded, it holds by its fore-paws while devouring, sitting up the while on its posterior. In drinking it is also said to lap water like a Cat. The Tarsier seldom makes any kind of noise, but when it does emit a sound, it is a sharp, shrill call. The female produces one, rarely two, young at a birth; these are similar to the parents. They are covered with hair, and have the eyes open. Mr. Hose further states that the mother often carries her young one about in her mouth, after the manner of a Cat. On the second day after its birth, the infant Tarsier can move about by itself. By the natives of Sumatra, and, indeed, of most of the islands inhabited by these animals, the Tarsiers are held in superstitious dread, their presence in the neighbourhood of the rice-fields being supposed to portend misfortune to the owner or to some member of his family.

Their elongated ankle-bones, and their leaping habits, seem to indicate that the Galagos and the Chirogales, or Mouse-Lemurs, are the nearest relatives of the Tarsiers.

THE TYPICAL LEMURS. FAMILY LEMURIDÆ.

Under this family heading are included the whole of the remaining members of the Sub-order. They all possess certain main characters in common; but on account of the presence or {23}absence of certain subordinate features in some of the groups, the family has been further subdivided into four sub-families. The more important characters which they have in common are the thick woolly fur, the Dog- or Fox-like snout and nostrils--a character obviously distinguishing them from the bulk of the Monkeys, in which the nose forms a subsidiary feature, and is not the main part of the face,--and especially the number and form of their teeth. In the centre of the upper jaw there is always a toothless gap, or _diastema_, on each side of which the teeth are arranged according to the following formula: I2/2, C1/1, P3/3, M3/3 = 36. Among the Endrinas, however, the formula is I2/2, C1/(1 or 0), P2/2, M3/3 = 32 or 30 in number. In the upper jaw the incisors are small and perpendicular; but in the lower, where they are long and narrow, they protrude horizontally in front, and then follow, parallel and close to them, the somewhat thicker canines, the six teeth together forming a comb-like series. The anterior pre-molar is always vertically longer than the others, and assumes the form and function of the canines in other animals.

In some genera (e.g., _Propithecus_), Milne-Edwards has observed that in the young animal the cerebellum is more overlapped by the cerebrum (or main brain) than it is later in life; and Dr. Major believes that the _Lemuridæ_ are highly specialised members of the Sub-order, developed from ancient types which were not unlike the American Monkeys of the family _Cebidæ_.

The Typical Lemurs are arranged in the following four sub-divisions: The Pottos and Slow-paced Lemurs (_Lorisinæ_); the Galagos and Mouse-Lemurs (_Galaginæ_); the True Lemurs (_Lemurinæ_); and the Endrinas (_Indrisinæ_).

{24}THE SLOW-LEMURS. SUB-FAMILY I. LORISINÆ.

This Sub-family has been constituted to receive a small number of Lemurs, which, although occupying limited areas in two widely separated continents--one genus being African and the others Asiatic--present certain characters in common. They are recognised by having soft woolly fur, a triangular head and pointed face, very large and staring eyes, set close together, while their ears are naked along their margin. Their fore- and hind-limbs are nearly equal. In the Asiatic genera the index finger is very small, while in the African it is quite rudimentary and nail-less. In both groups the thumb diverges widely from the other fingers, and the great toe is directed backwards, but the ankle-bones of the foot are not elongated. The tail is either so short as to be quite concealed in the fur, or is less than one-third of the length of the body.

In the skull the squamosal region with the outer and posterior portion of the ear capsules (the periotic) are inflated. The dental formula of the Slow-Lemurs is the same as given above for the family generally. In the upper jaw, the two incisors are usually equal, but, if unequal, the inner incisor is always the larger (Fig. 6); the vertically long canine, which is separated by a gap from the anterior pre-molar, presents both in front and behind a neck or cingulum, which is cusped behind; the pre-molars are canine-like, and have the cingulum produced behind into a heel (or talon). The anterior of the three is {25}vertically longer than the median, while both the median and posterior have, to the outside, one main cusp with a minute one on each side of it, and two inner cusps; the molars are all cingulate, and have to the outside two main cusps (separated by a minute cusp) and two inner cusps, the outer and inner cusps alternating. Of the anterior and median molars, the two main outside cusps are sub-equal, and are flanked on each side by a minute cusp; the posterior molar is short and wide, and has only one minute cusp in front of its anterior main cusp. Of the lower jaw, the pre-molars are canine-like, the anterior being vertically long and having a posterior heel; the posterior pre-molar, which differs in size from the anterior, presents two main cusps to the outside and one minute cusp in front; the molars, both anterior and median, are four-cusped, with a minute cusp in front, the posterior being five-cusped, while all have their front cusps vertically taller than the hind ones.

Among the _Lorisinæ_ the dorsal and lumbar vertebræ together number from twenty-one to twenty-three. The cæcum, at the junction of the larger and smaller intestine, is long. The main artery of the fore- and hind-limbs breaks up into a _rete mirabile_ of numerous small parallel branches.

The Slow-Lemurs are distributed in the western parts of the African continent, and in the Indian, Malayan and Indo-Chinese portions of the Oriental region. It is a remarkable fact that this group should be confined to one portion of Africa and be entirely absent from Madagascar, the country where the Lemurs form so characteristic a feature in the fauna.

The _Lorisinæ_ embrace three genera, the Pottos (_Perodicticus_) from the African continent; the Slender Loris (_Loris_), and the Slow-Loris (_Nycticebus_), both of which inhabit the Oriental region.

{26}THE POTTOS. GENUS PERODICTICUS.

_Perodicticus_, Bennett, P. Z. S., 1839, p. 109; Huxley, P. Z. S., 1864, p. 235.

_Arctocebus_, Gray, P. Z. S., 1863, p. 150; Mivart, P.Z.S., 1864, p. 644.

This genus contains two species, both confined to the West Coast of Africa. The Pottos are slender-bodied animals, with oval heads and blunt Dog-shaped muzzles. Their eyes are large and full, and their external ears erect, with shelf-like lamellæ inside. They have slender and sub-equal limbs. The second digit of the fore-limb is rudimentary and nail-less; it is supported on one wrist-bone, and has two phalanges or finger-bones. The great toe is opposable, and the fourth and fifth digits of both limbs are united together by membrane as far as the first joint. The processes of the vertebræ in the neck and back are long and protruding. The tail is very short.

The pre-maxillæ (which carry the incisor teeth) do not project in front, nor does the bony palate extend farther back than the end of the posterior molar teeth. Of the upper teeth the incisors are equal in size (Fig. 6); the median and posterior pre-molars have on their crowns three cusps, of which the two outer are the larger; the anterior and median molars are cingulate, have four-cusped crowns, and are larger than the pre-molars; the posterior is narrow from before backwards, and its crown presents only two or three cusps. Of the lower teeth, the anterior pre-molar is recurved and larger than the canine, with a ridge on its inner face and a cusped heel behind; the median and posterior ones are shorter than their anterior fellow, each having a strong posterior cusped heel; the anterior and median {27}molars have their crowns four-cusped and are nearly equal in length; the crown of the posterior molar is 4-5-cusped, and has a ridge joining its anterior heel to its front outer cusp. Transverse and oblique ridges are well marked on the crowns of both the upper and lower cheek-teeth.

I. THE CALABAR POTTO. PERODICTICUS CALABARENSIS.

_Perodicticus calabarensis_, Smith, Proc. Roy. Phys. Soc., Edinb., 1860, p. 172, figs. 1, 2.

_Arctocebus calabarensis_, J. E. Gray, P. Z. S., 1863, p. 150; Huxley, P. Z. S., p. 314, pl. 28 (1864).

_Nycticebus calabarensis_, Schlegel, Mus. Pays Bas, vii., p. 287 (1876).

CHARACTERS.--Hair long, wool-like; face, hands, and feet thinly haired. Head 2½ inches long, tapering in front; muzzle prominent and blunt; ears large, pointed, and projecting above the level of the head, with short hairs, two lamellæ inside, and marginal tufts; neck short; hind-limbs slightly larger and {28}longer than the fore-limbs; hands smaller than the feet; thumb thick, with a tubercle at base; the wrist-bone of the very rudimentary index-finger supporting two rudimentary finger-bones; third finger not parallel to fourth and fifth; the fourth longest (Fig. 7). Great toe with a tubercle at its base, opposable. Tail ¼ inch long, hidden in the fur of the body.

Fur grey at base of hairs, fawn-coloured farther up, and tipped with dark brown, uniform over the body and limbs; face darker; sides of head lighter; line from brow down the nose white. No vibrissæ on face and no eyebrows; chin, throat, inner surface of limbs, and under side of body, greyish-white.

Posterior upper molar nearly equal to posterior pre-molar, with the hind inner cusp of the crown rudimentary. Lower incisors not visible beyond the lip, cingulate; posterior molar five-cusped and relatively larger than in the next species (_P. potto_). Bony palate with large perforations behind the incisors. Intestines, 40 inches long; cæcum, 2½ inches.

DISTRIBUTION.--The "Angwantibo," as this species is called, is known only from Old Calabar, on the west coast of Africa.

II. BOSMAN'S POTTO, PERODICTICUS POTTO.

_Potto_, Bosman, Beschrijving van de Guinese Goudkust, ii., p. 32, fig. 4 (1704).

_Nycticebus potto_, Geoffr., Ann. Mus., xix., p. 165 (1812); Schlegel, Mus. Pays Bas vii., p. 287 (1876).

_Perodicticus geoffroyi_, Bennett, P. Z. S., 1830, p. 109.

_Perodicticus potto_, V. der Hoeven, Tijdschr. v. Natuurl. Gesch., xi., p. 41 (1844); Wagner, in Schreber's Säugeth. Suppl., v., p. 183 (1855).

_Stenops potto_, Pel, Bijdragen tot de Dierkunde, 1852, p. 41.

CHARACTERS.--More common than the Angwantibo and {29}distinguished from it by its rounder, shorter, and wider head, less produced muzzle, smaller mouth, and eyes farther apart; ears shorter, rounder, and directed more backwards, with one lamella on the inner surface. Hands longer, flat and thin; index-finger not so reduced as in _P. calabarensis_. Tail very short, little more than an inch long, but visible beyond the fur. Length of body, 8 inches.

Upper pre-molars less canine-like than in the preceding species; posterior upper molar differing in size from and set farther out than the others, short and wide, with the crown elliptical and only two-cusped, the two hind-cusps wanting. Lower incisors more prominent and projecting than in _P. calabarensis_; crown of posterior lower molar four-cusped.

ADULT.--Upper surface rich reddish-brown with a black dorsal stripe widening opposite the shoulders, and fading out towards the tail; under side yellowish or reddish-white. Hair on face shorter and paler, with a dark ring round the eyes.

YOUNG.--Reddish-brown all over, redder on the back of the head and neck, darker on the shoulders; creamy-white, washed with rufous, beneath.

Fur silver-grey at the base of the hairs, with reddish-brown tips in younger, and dark golden-brown in older, individuals.

DISTRIBUTION.--The Potto is one of the oldest known members of the Lemuroid group, having been described in 1704 by Bosman, who met with it on his voyage to Guinea. It was, however, lost sight of until 1825, when it was rediscovered in Sierra Leone and fully described by Bennett in 1830. It is known also from Gaboon.

HABITS.--Both species of Potto are nocturnal and arboreal, and are exceedingly slow in their movements. In catching {30}insects or flies, which form part of their food, they proceed with extraordinary deliberation, never quickening their movements, and yet rarely, if ever, missing their prey.

Bosman in his description of the Gold Coast of Guinea, gives a woodcut of the Potto, which, he says, is a "Draught of a Creature, by the _Negroes_ called _Potto_, but known to us by the Name of Sluggard, doubtless from its lazy, sluggish Nature; a whole day being little enough for it to advance ten Steps forward.

"Some Writers affirm, that when this Creature has climbed upon a Tree, he doth not leave it until he hath eaten up not only the Fruit, but the leaves intirely; and then descends fat and in very good case in order to get up into another Tree; but before his slow pace can compass this, he becomes as poor and lean as 'tis possible to imagine: And if the trees be high, or the way anything distant, and he meets with nothing on his journey, he inevitably dies of Hunger, betwixt one tree and the other. Thus 'tis represented by others, but I will not undertake for the Truth of it; though the _Negroes_ are apt to believe something like it.

"This is such a horrible ugly Creature that I don't believe anything besides so very disagreeable is to be found on the whole Earth; the Print is a very lively Description of it: Its Fore-feet are very like Hands, the Head strangely disproportionately large; that from whence this Print was taken was of a pale Mouse colour: but it was then very young, and his Skin yet smooth, but when old, as I saw one at _Elmina_ in the year 1699, 'tis red and covered with a sort of Hair as thick set as Flocks of Wool. I know nothing more of this Animal, than that 'tis impossible to look on him without Horrour, and that he hath nothing very particular but his odious Ugliness."

{31}THE SLENDER LORIS. GENUS LORIS.

_Loris_, Geoffr., Mag. Encycl., Ann. 2, i., p. 48 (1796).