58 



MUSEUM OF ANIMATED NATURE. 



("Jerboas. 



seen the dormouse open with its teeth the hard shell 

 cf a nut, and clear it out with great address. The 

 dormouse hybernates, and hoards up a store of pro- 

 visions in holes, and the crevices about the roots of 

 trees, &c., to which to have recourse in the winter ; 

 for its torpidity is not without interruption. A mid- 

 day gleam of sunshine rouses it up in its snug retreat ; 

 and invites it forth, when it takes a little food ; on 

 the diminution of the temperature it betakes itself to 

 its dormitory, and rolling up itself into a ball, sinks 

 into a profound slumber. In this condition it may 

 be handled, or rolled about a table, if not exposed 

 to the influence of warmth, without being roused 

 from its trance. It is not until the spring has fairly 

 set in that the dormouse regains its full activity, 

 and it is at this period that its magazine is of the 

 greatest service : for without a store thus provi- 

 dently accumulated, it would, for some time at least, 

 be straitened for food. 



The head of this species is proportionately large ; 

 the eyes are large, black, and prominent : the ears 

 are broad ; and fur soft ; the tail long, fringed with 

 hair on each side, and somewhat tufted at the end ; 

 the body plump ; the limbs short. General colour 

 cinnamon red, passing into pale yellow below. The 

 young are of a mouse grey. Length of the head 

 and body two inches eight lines; of the tail, two 

 inches six lines. 



435. — The Garden Dormouse, or Lerot 



(Myoxus Niteld). The Greater Dormouse of Shaw. 

 This species is a native of the whole of the tempe- 

 rate portions of continental Europe, and indeed it is 

 found as high north as Poland and Prussia. In 

 France it is very common, gardens and orchards 

 being its favourite abode : it makes sad havoc among 

 wall-fruits, attacking peaches, apricots, pears, &c, 

 with great avidity. Its winter store, however, con- 

 sists of nuts, pea's, beans, and the like, which are 

 collected in great abundance, and stowed away in 

 some convenient recess, where eight or ten indi- 

 viduals assemble to pass away the colder season 

 in sleep. The summer nest of the Lerot, in which 

 it rears its young, is built in the holes of walls or 

 the chinks of aged trees. The young are four or 

 five in number. The colour of this pretty but an- 

 noying creature is reddish grey ; beneath, white ; 

 a black patch surrounds the eye, and spreads be- 

 hind the ear. The tail is covered with short black 

 hair, except at the end, which is tufted with white. 

 Length of head and body four inches and a half; 

 of the tad, four inches. 



236. — The Cape Graphxbre 



(Graphiurus Capensis). The genus graphiurus is 

 scarcely to be separated from Myoxus : it is repre- 

 sented by the Cape Graphiure, a native of South 

 Africa. This species is about the size of the lerot, 

 which it much resembles in the style of its colour- 

 ing, the general tint above being of a deep brown- 

 ish grey ; the muzzle and sides of the face reddish 

 white ; under parts greyish white, with a tinge of 

 red ; tail brown, the tip, which is not tufted, reddish 

 white ; a band of blackish brown extends from the 

 eyes to the base of the ears. 



THE JERBOAS 



(Dipus). The Jerboas constitute a group of the 

 great murine section of Rodents, and termed by 

 Mr. Waterhouse Dipodidae, of which, he observes, 

 the genera Dipus, Alactaga, and Meriones are ex- 

 amples. 



All the animals of this tribe are remarkable for 

 sthe shortness of the fore limbs, the development of 

 the hinder limbs, and the length and slenderness 

 of the metatarsus ; they resemble in these points 

 the kangaroos. They bound along on their hind 

 limbs with great rapidity, and appear almost to 

 skim, like birds, the flat plains or sandy wastes 

 where they take up their abode. In an elaborate 

 memoir by M. F. Cuvier on the Jerboas and Ger- 

 billes he divides these animals into different ge- 

 nera.' The jerboas (Dipus) have only three toes 

 on the hinder feet, and these, as in birds, are ar- 

 ticulated to a single elongated metatarsal bone, 

 commonly known as the canon-bone. In the Alac- 

 ta°-as there are five toes ; of these the three central 

 are articulated to a single metatarsal bone, while 

 the other two have each their own slender meta- 



+OVOQ 1 hnnp 



In Meriones and Gerbillus the toes are five, each 

 with their own distinct metatarsal bone. The in- 

 cisors of the Alactagas are simple, whilst those in 

 the upper jaw of the jerboas are divided longi- 

 tudinally by a furrow. The molars of the latter 

 genus are complicated in form, and but little re- 

 semble those of the former. They are four in num- 

 ber in the upper jaw, and three in the lower ; but 

 the first in the upper is a small rudimentary tooth, 

 which probably disappears in aged individuals. 

 After a detailed account of the structure of the 

 grinding teeth, M. Cuvier observes that the general 



structure of the head of the Alactagas and jerboas 

 is evidently the same, and is characterized by the 

 large size of the cranium, the shortness of the 

 muzzle, and, above all, by the magnitude of the 

 suborbital foramina. The cranium of the jerboa 

 is distinguished by its great breadth posteriorly, 

 resulting from the enormous development of the 

 tympanic bone, which extends beyond the occipital 

 posteriorly and laterally, as far as the zygomatic arch, 

 which is by no means the case in the Alactagas, 

 where all the osseous parts of the ear are of mode- 

 rate dimensions. Another differential character 

 between the two genera is presented by the max- 

 illary arch, which circumscribes externally the sub- 

 orbital foramina, and which in the Alactagas may 

 be said to be linear, presenting a very limited sur- 

 face for the attachment of muscles. He then notes 

 a difference in the relative development of the 

 jaws, the lower being comparatively much shorter 

 in the Alactagas than in the jerboas. Having de- 

 scribed a new specis of Alactaga, a native of Bar- 

 bary, under the name of Alactaga arundinis, M. F. 

 Cuvier proceeds to consider the characters and 

 affinities of the genera Gerbillus and Meriones, and 

 enters into a critical examination of all the species 

 referred to those genera, and comes to the conclu- 

 sion that they have a closer affinity with the true 

 Muridse than with the jerboas and Alactagas. 

 Fig. 237 represents the skull and teeth of Dipus 

 hirtipes: a, skull, profile; b, the same seen from 

 above ; c, the same seen from below ; d, e, the 

 teeth. 



Fig. 238 represents the skull and teeth of Alac- 

 taga; a, and b, the cranium, one-third larger than 

 the natural size ; c, and d, the teeth, five times en- 

 larged. 



239, 240, 241 , 242.— The Egyptian Jerboa. 



{Dipus JEgyptius) . In the true jerboas the head is 

 large, and not unlike that of a rabbit in form ; the 

 ears are long and somewhat pointed ; the eyes are 

 full and prominent; the tail is very long, cylindri- 

 cal, and covered with short hair except at the ex- 

 tremity, which is tufted. The fur of the body is soft 

 and delicate ; the whiskers are long, the fore feet 

 are very small, and have four toes and the rudi- 

 ment of a thumb, furnished, however, with a nail. 

 In the hind feet of these animals we behold palpa- 

 ble evidences of their express adaptation to the 

 deserts where they habitually reside. Not only is 

 the metatarsal portion of the foot extremely elon- 

 gated, but the toes are clad on the under surface 

 with long bristly hairs, which while they add to 

 their span, and give firmness and security to their 

 tread on a loose and yielding surface, defend the 

 foot from the heat of a glowing waste beneath a 

 fervid sun. 



The Egyptian Jerboa is found in Egypt, Barbary, 

 Nubia, and the warmer parts of Syria and Arabia. 

 It lives in troops, which colonize the most arid parts 

 of the desert, where, on hillocks of sand or the 

 crumbled heaps of ruins, they work out long burrows 

 in which to dwell. In these burrows they make 

 their nests and rear their young. So powerful are 

 their teeth, that they not only gnaw in a short time 

 through the hardest wood, but, as Sonniui affirms, 

 through thin layers of stone beneath the sand. 

 According to some, these animals are nocturnal in 

 their habits, stealing forth to feed and sport when 

 evening begins to close. They are, however, not 

 altogether nocturnal, for Sonnini observed them in 

 broad day playing around the mouths of their sub- 

 terranean habitations, and he particularly noticed 

 that those which he kept delighted to bask in the 

 sun, and were always lively in that situation. The 

 jerboas are very timid creatures, and hasten to their 

 burrows for security on the least noise : if inter- 

 cepted, they trust to their speed, and seem to fly 

 across the plain ; so great indeed is the rapidity with 

 which they bound along, that a greyhound has some 

 difficulty in the chase." In making each leap they 

 spring from the hind feet, the impulse being given 

 by the powerful muscles of the thighs, while the tail 

 serves as a balance and rudder. In the act of spring- 

 ing the fore paws are pressed close to the chest ; 

 they descend, however, upon them, but such is the 

 quickness of the leap, and the celerity with which 

 they recover their due posture, and spring again, 

 that the eye is completely deceived, for it appears 

 as if they never used the fore paws at all, but alike 

 sprang from and alighted on their long slender hind 

 legs alone. When undisturbed, their common atti- 

 tude is that of sitting up on the haunches ; and the 

 fore paws are used in the same manner as in the 

 squirrels and marmots. The food of the jerboa 

 consists principally of bulbous roots, which the 

 animals digup with theirforepaws ; they also devour 

 grain and other vegetable matters. It would appear 

 that the jerboa hybernates, but the duration of its 

 torpor cannot be very protracted. 



The flesh of these animals, though unsavoury, is 

 eaten by the Arabs and Egyptians, who contrive to 

 capture them by stopping up all the openings of 



their subterranean retreat except one, which is 

 netted. 



Few animals, if we may judge from our own ob- 

 servations, bear confinement so impatiently as the 

 jerboas : they sedulously exclude themselves from 

 observation, and when they come forth from their 

 retreat in the evening, they are restless and distrust- 

 ful in the extreme. 



In size this species is equal to a large rat; the 

 general colour is pale tawny yellow, passing into a 

 lighter tint beneath ; the terminal tuft of the tail is 

 black, merging at the tip into white ; a white or 

 whitish strip appears on each of the buttocks below 

 the base of the tail. 



243, 244. — The Dark-banded Jerboa. 

 Of this jerboa, which is figured by Shaw under 

 the name of " the jerboa," we have never seen an 

 example. It is neither noticed nor figured byLich- 

 tenstein, who has published the best monograph of 

 these animals that has yet appeared. For ourselves 

 we have no doubt but that the original figure was 

 taken from a specimen of the Egyptian Jerboa, in 

 which the abrupt border to the white mark was 

 darker than usual ; for in some instances the back is 

 washed with a dusky tint, which has a tendency to 

 assume wavy transverse bands, one of which, on the 

 haunch, as it is said, is occasionally distinct. 



With regard to the Alactagas, to which we have 

 alluded, the typical species, the Siberian Alactaga 

 (Dipus Jacnlus, Gmel. ; the Alactaga, Buff. ; the 

 Siberian Jerboa, Pennant), is distributed from 

 Arabia, through Persia, Tartary, anil Turkey, and 

 as far north as the Volga and Irtish. It inhabits the 

 plains and flat districts, where it makes extensive 

 burrows ; in general habits it resembles the common 

 jerboa of Egypt, but is of larger size. 



Its food is stated to consist not only of vegetable 

 but also of animal substances, as small birds and 

 insects ; and, as we learn from Pallas, it spares not 

 even its own species. The subterranean habitations 

 of these animals are extremely capacious, and 

 formed about half a yard below the surface of the 

 ground. The passage leading to them is of great 

 length, and pursues a circuitous course, having at 

 intervals additional shafts or openings upwards, 

 affording extra facilities for escape in the event of 

 danger. During the winter they hybernate ; retiring 

 to their subterranean chambers, they shut up the 

 openings, and sink into a complete state of lethargy. 

 It is affirmed by Gmelin that when their burrows 

 are opened at. this season a quantity of grain, dried 

 shoots, and herbs are found within them ; on the 

 contrary, Pallas affirms that they collect no stores 

 of provision for the winter. It is possible that both 

 these naturalists, who had ampel opportunities of 

 investigating the habits of the Alactaga in a state 

 of nature, may be correct, and that in the more 

 northern districts of its range it may accumulate a 

 store of provision, for use in the spring, when it 

 first rouses from its torpidity. The Alactaga is more 

 numerous and fertile in the warmer than in the 

 colder latitudes; but it is nowhere to be seen in 

 sitch numbers as the Egyptian Jerboa. From its 

 large size and the superior flavour of its flesh, it is ' 

 more sought after, as food, than that animal, and is 

 chased, and also taken by stratagem, by the Arabs 

 and Tartars. Such is its swiftness that it appears to 

 skim the plain without touching the ground ; even 

 a mounted horseman on a fleet steed can scarcely 

 overtake it. The fur of the Alactaga is extremely 

 soft and fine ; on the upper parts it is of a pale 

 fawn yellow, clouded with greyish brown on the 

 lower part of the back; a white crescentic line ex- 

 tends on each side of the crupper, below the root of 

 the tail. The under parts of the body and inside of 

 the limbs are white ; the tail is brown, except the 

 tuft at the extremity, which is black tipped with 

 white. 



245. — The Labrador Jumping Mouse 

 {Meriones Labrador icus). This species appears to 

 be the Labrador rat of Pennant; the Gerbillus 

 Hudsonius of Rafinesque ; Mus Labradorius of 

 Sabine ; Gerbillus Labradorius of Harlan ; the La- 

 brador Jumping Mouse of Godman ; and Katse (the 

 Leaper) of the Chepewyan Indians. 



The genus Meriones in dental formula differs in 

 some points from Dipus. The upper incisors, of a 

 deep orange-colour, are marked with a longitudinal 

 furrow; the molars are four on each side above, 

 and three below ; the first above is very small ; the 

 surfaces of the rest in both jaws are marked with 

 irregular winding lines of enamel (see Fig. 24G). 

 The muzzle is narrow and elongated ; the ears 

 rounded, the hind limbs considerably developed ; 

 the tail long, ringed with scales, and thinly covered 

 with short hair. 



The Labrador Jumping Mouse, which was first 

 described by Pennant in his 'Arctic Zoology,' is 

 very common in the fur countries of North America, 

 as far north as the Great Slave Lake, and perhaps 

 farther; but of its habits we have no precise details. 



