154 



RUMINANTIA. MAMMALIA. RUMINANTIA. 



to assign to them. "These animals inhabit trees," 

 says Cuvier, " and never remove from that on which 

 they are located until they have stripped it of every 

 leaf, so painful to them is the requisite exertion to reach 

 another I " Our readers are well aware how frequently 

 these errors have been exposed by Bell, Blyth, Buck- 

 land, Broderip, Owen, and a host of other distinguished 

 English writers; nevertheless we have pleasure in quot- 

 ing some apt remarks of the last-named authority, 

 recently given in his manual of the " Skeleton and 

 Teeth." Alluding to the Ai, Professor Owen observes 

 that " it is less able to raise its trunk above its limbs 

 than the seal, and can only progress by availing itself 

 of some inequality of the soil offering a holdfast to its 

 claws, and enabling it to drag itself along. But to 

 judge of the creative dispensations towards such an 

 animal by observation of it or report of its procedure 

 under these unnatural circumstances, would be as 

 reasonable as a speculation on the natural powers of 

 a tailor suddenly transferred from his shopboard to the 

 rigging of a ship under weigh, or of a thorough-bred 

 seaman mounted for the first time on a full blood-horse 

 at Ascot. Rouse the prostrate Sloth, and let it hook 

 on to the lower bough of a tree, and the comparative 

 agility with which it mounts to the topmost branches 

 will surprise the spectator. In its native South Ame- 

 rican woods, its agility is still more remarkable, when 

 the trees are agitated by a storm. At that time the 

 instinct of the Sloth teaches it that the migration from 

 tree to tree will be most facilitated. Swinging to and 

 fro, back downwards, as is its habitual position, at the 

 end of a branch just strong enough to support the 

 animal, it takes advantage of the first branch of the 

 adjoining tree that may be swayed by the blast within 

 its reach; and stretching out its fore-limb, it hooks itself 

 on, and at once transfers itself to what is equivalent to 

 a fresh pasture. The story of the Sloth voluntarily 

 dropping to the ground, and crawling under pressure 

 of starvation to another tree, is one of the fabulous 

 excrescences of a credulous and gossiping zoology." 

 Such, in brief, is a fair estimate of the capabilities of 

 the Ai in a state of nature ; and the testimony of such 

 trustworthy travellers as Stedman and Waterton as to 

 its power of rapid motion under certain circumstances, 

 has long placed the matter beyond dispute. " He 

 travels at a good round pace," says the latter, " and 

 were you to see him, as I have done, passing from tree 



to tree, you would never think of calling him a sloth." 

 In conclusion, we may remark, that the female is fur- 

 nished with two mammae, and produces one young at 

 a single birth, which adheres to the parent by its claws 

 until able to shift for itself. The Ai is much sought 

 after by the natives, who consider the flesh to be 

 excellent eating. When on the move it utters a short 

 plaintive cry resembling our pronunciation, in a shrill 

 voice, of the two-lettered name by which it is appro- 

 priately called. 



THE GIPAXEIOTT (Bradypus torquatus} is, like the 

 above, a native of the north-easterly districts of Brazil, 

 but it occurs more sparingly. The fur exhibits a friz- 

 zled, ferruginous aspect along the under parts of throat 

 and belly; but above it has an orange-yellow colour 

 generally, whilst the face is black and destitute of hair. 

 A more characteristic feature is seen in the presence of 

 a deep black band, forming a sort of collar round the 

 neck ; its specific distinctness being rendered still more 

 certain by differences observable in the structure of the 

 cranium, compared with that of other sloths. The habits 

 of the Gipakeiou closely resemble those of the ai. 



THE UN ATT (Cholcepus didactylus), or Two-TOED 

 SLOTH, has been generically separated by Uliger from 

 the above-described species, on account of certain pecu- 

 liarities in the teeth, associated with a comparative 

 elongation of the head on the one hand, and a short- 

 ening of the anterior pair of limbs on the other. The 

 fore-feet are, as above indicated, furnished with only 

 two digits ; and the tail, which in the ai is reduced to 

 a mere stumpy appendage, is altogether wanting in the 

 Unau. The first molar teeth of this animal are long, 

 and sufficiently acuminated at the summit to resemble 

 ordinary canines, whilst the superior pair, during the 

 closure of the jaw, are placed in front of the lower ones. 

 Besides these spurious canines, there are fourteen other 

 molars, four on either side above, and three on either 

 side below, the crowns of which are wedge-shaped, that 

 is to say, in their worn condition. In regard to the 

 skeleton, its clavicles are fully developed, and the bones 

 of the carpus and tarsus become very early consolidated 

 together. The Unau is about half as large again as 

 the common ai, whilst the fur exhibits a dark-greyish 

 brown colour generally, being here and there tinged 

 with red. A living specimen of this singular species 

 may be seen in the London Zoological Society's Gar- 

 dens, Regent's Park. 



ORDER IX. EUMINANTIA. 



THROUGHOUT the entire mammalian series, there is not 

 a better defined group than that formed by the rumi- 

 nating quadrupeds here associated together under the 

 above distinctive title. This was the opinion of the 

 greatest of French naturalists, and it is in no degree 

 contra-indicated by Professor Owen, in whose more 

 exacting system of classification an outline of which is 

 given at page 8 these cud-chewing species collectively 

 maintain their zoological continuity, as a subordinate 

 division of the even-toed ungulates more precisely 

 called Artiodactyla. 



The essential features by which the ruminants may i 

 be distinguished are not confined merely to one or two j 

 trifling characters, but involve the structure and mor- 

 phology of several important organs and appendages. 

 In a few words they may be stated as follows : All 

 the feet terminate in two digits, the ultimate phalange 

 of each being armed with a tightly investing hoof; and 

 the opposed surfaces of these hoofs are flattened in such 

 a way as to impart to the foot an appearance of splitting 

 in the mesial line. With an exception in the case of 

 the camels, all the species are destitute of incisive | 



