A I L A N T U S. A I L U R U S. 



teeth in cither jaw ; four molars and one canine in 

 each side of the upper jaw, and three molars and one 

 canine in caeh side of the lower. The whole teeth 

 nearly of the same form cylindrical, of soft bone 

 cased with enamel, but with no plates of enamel in 

 their substance. They are not, therefore, adapted 

 cither for biting or for grinding, but merely for 

 pulling off the leaves, which are taken into the sto- 

 mach with little preparation in the mouth. The 

 stomach consists of the same number of divisions as 

 that of the ruminating animals, but the sloths do not 

 ruminate. There are only three toes on each of the 

 feet, the bones of these, answering to the little finger 

 and the thumb, being merely rudimental, and united 

 to the bones of the palm, which also become soldered 

 together long before the natural death of the animal. 

 The fore legs are very long, nearly double the length 

 of the hind ones, and the neck is usually described as 

 consisting of nine vertebrae, while in all the other 

 mammalia, as far as is known, it consists only of 

 seven. This last character is, however, incorrect : 

 there being only seven cervical vertebrae, or those 

 without articulated processes ; but the first and se- 

 cond dorsal vertebrae follow (naturally enough when 

 the habit is considered) the structure of birds, and the 

 ribs attached to them are not joined to the sternum. 

 This formation allows of more motion to the head, 

 which is raised upwards, and rests on, or is received, 

 between the fore legs, when the animal hangs from 

 the branches asleep. The young is brought forth on 

 the trees, and hangs suspended to the mother, whose 

 teats are pectoral and two in number, till it is able to 

 suspend itself from the branches, and find its 

 own food. There is, indeed, a curious jumble of 

 resemblance to some parts of the human structure in 

 these very curious animals. Two species are described, 

 similar in habits, though differing in appearance ; 

 and there are probably more species, or at least 

 varieties. The places which they inhabit are very 

 difficult to explore ; and therefore their numbers and 

 habits are but imperfectly known. 



Ttic common Ai, of which the following figure is 

 a representation, appears to be the most abundant 



The Ai; or, common Sloth. 



species, or, at all events, the one which is best and 

 has been longest known. It is about the size of a 

 large cat, with the head short and round, the face 

 yellowish, with brown rings round the eyes, which 

 give them the appearance of being placed un- 

 der an eye-brow. The face is covered with 

 very short hair ; but that upon the rest of the head, 

 the body, and the feet, down to the very claws, 

 is long, shaggy, and of a very peculiar texture. It is 

 turned back from the face, and divided from a centre 

 near the topjrf the head, something similar to the 



crown of the human head, and all over the rest of the 

 body it is matted. The form is very peculiar, being 

 slender at the roots and flattened at the points, as if 

 every pile was a blade of grass, inserted by its narrow 

 point. It wants the gloss of ordinary hair upon the 

 living subject, and feels sapless and dead, as if it con- 

 sisted of withered vegetable fibres. The colour is 

 grey, but variously marked, and mottled with black, 

 brown, and white, not unlike a portion of a tree 

 covered with lichens ; and in its colours, and also the 

 length of the hair, it is liable to considerable varia- 

 tions ; but whether of age, sex, season, or difference 

 of exposure, has not been ascertained. 



The collared Ai has the head not quite so rounded, 

 the muzzle a little more produced, the face black, a 

 black collar round the neck ; the hair on the head 

 yellow, on the rest of the upper part orange, and on 

 the breast and upper part of the belly rust colour. 

 The hair on the head is more produced than on any 

 other part ; and over the whole animal is not so flat- 

 tened, shaggy, and withered, as in the common species. 



Both are inoffensive animals, following their curi- 

 ous mode of life in the forests without offering the 

 slightest violence to any living creature. When the 

 air is dry, hot, and still, they are mostly at rest 

 during the day, and their suspension from the under 

 sides of the boughs protects them alike from the 

 action of the sun and from enemies. Whether in 

 that state of the weather they move more during the 

 night has not been ascertained ; but it is probable 

 that they do, as the leaves of the trees are then 

 refreshed by the dew. As has been already men- 

 tioned, the increasing of the storms puts them in 

 motion, and they then utter their plaintive cry, 

 of which the name "ai" is a pretty close imita- 

 tion. They are very tenacious 01 life, more so than 

 most of the mammalia. Their clutch is also formi- 

 dable, if they are attacked on the ground, where 

 they throw themselves on their backs, and defend 

 themselves with the extremities of the paws with 

 the greatest resolution ; and if they seize hold, they 

 do not quit it till the enemy is dead. 



The habits of these animals are not only interest- 

 ing as being characteristic of some of the thickest and 

 most entangled forests now remaining on the globe ; 

 but as, in so far, indicating what must have been the 

 state in former times of those portions of it where 

 the skeletons of animals of the same family, but as 

 large as that of the elephant, are found in the ground. 

 See MEGATHERIUM and MEGALONYX. 



AILANTUS (Linnaeus). Two very beautiful 

 Chinese trees, one hardy enough to bear the climate of 

 England, usually raised from imported seeds; the 

 other requires the protection of a hot-house. Lin- 

 ncean class and order, Polygamia Dicccia. Natural 

 order, Terebinthaccce. Generic character : male flow- 

 ers calyx, one-leafed, five-parted, very small ; corolla 

 five petals, acute, convolute at the base ; stamina, 

 filaments ten, compressed, the length of the corolla. 

 Female flowers calyx as in the male ; corolla as in the 

 male; styles lateral; capsules compressed ; seeds soli- 

 tary, lens-shaped. Bisexual flowers as on the above. 



AILURUS. (Literally " parti-coloured tail," 

 though the same was one of the Greek names for the 

 common domestic cat, and no doubt applied to those 

 varieties which have the tail marked with a series of 

 rings of different colours.) A genus of mammalia, 

 belonging to the order carnivora, or preyers upon 

 flesh, properly so called, and of the family of planti- 



