the ears and hind limbs. It is found in all parts of Europe except the north of Russia, the Scandinavian peninsula, and Ireland.

fur is usually of a tawny gray colour above and white beneath, with the upper surface of the short tail and the tips of the ears black. The colour of the fur differs, however, considerably in different latitudes and at different seasons of

the year; showing a tendency

to become white

Its

during winter in northern countries, while assuming a reddishyellow hue in the more genial climate of southern Europe. The Hare is a nocturnal animal, remaining during the day on its "form," as the slight depression is called which it makes in the open field, usually among grass.

The Mountain Hare (L. variabilis) is found throughout the

northern part of the Palearctic region, ranging from Ireland in the west to Japan in the east, and also occurring in several of the more southerly mountain ranges, such as the Pyrenees, the Alps, and the Caucasus. It is smaller than the common species, with a smaller and more rounded

head, and shorter ears, tail, and hind limbs. In cold climates the colour of the whole animal changes in the winter to a pure white

(as in Fig. 218), with the exception of the tips of the ears, which remain black. In Ireland no winter change of colour takes place.

The Rabbit (L. cuniculus), speaking of the wild race only, is distinguished from the Hare externally by its smaller size, shorter ears and feet, the absence or reduction of the black patch at the tip of the ears so characteristic of the Hare, and by its grayer colour. The skull is smaller and lighter, with a slenderer muzzle and a longer and narrower palate. Besides these characters, however, the Rabbit is sharply separated from the Hare by the fact that it brings forth its young naked, blind, and helpless; to compensate

for this, it digs a deep burrow in the earth in which they are born and reared, while the young of the Hare are born fully clothed with fur, and able to take care of themselves in the "form" in which they are born. The weight of the Rabbit is from 2 to 3 lbs., although individuals perfectly wild have been recorded up to more than 5 lbs. Its general habits are too well known to need a detailed description here. It breeds from four to eight times a year, bringing forth each time from three to eight young. Its period of gestation is about thirty days, and it begins to breed when six months old. It attains to an age of about seven or eight years.

The geographical distribution of the Rabbit presents many most interesting peculiarities. It is believed to be originally a native of the western half of the Mediterranean basin only, and still abounds in Spain, Sardinia, Southern Italy, Sicily, Greece, Tunis, and Algeria; and many of the Islands adjoining these countries are quite overrun

with it. Thence it has spread, partly by man's agency, northwards throughout temperate Western Europe, increasing rapidly wherever it gains a footing; and this extension is still going on, as is shown by the case of Scotland, in which sixty years ago Rabbits were little known, while they are now found in all suitable localities up to the extreme north. It has also gained admittance into Ireland, and now abounds there as much as in England. Out of Europe the same extension of range has been going on. In New Zealand and Australia Rabbits, introduced either for profit or sport, have increased to such an extent as to form one of the most serious pests that the farmers have to contend against, as the climate and soil seem to suit them perfectly, and their natural enemies are too few and too lowly organised to keep their numbers within reasonable bounds. In other cases Rabbits introduced into islands have become or remained more or less distinct from their parent stock; thus the Rabbits both of the Falkland Islands and of Jamaica still show traces of their descent from domesticated varieties, and have never reverted to the ordinary brownish-gray type. And again, as was pointed out by Mr. Darwin,1 the Rabbits in the island of Porto Santo, near Maderia, whose ancestors were introduced from Spain in 1418 or 1419, have formed quite a distinct diminutive race, barely half the bulk or weight of English Rabbits, and differing in certain slight details of colour and habits.

Bibliography of Rodentia.-G. R. Waterhouse, "Observations of the Rodentia," Mag. Nat. Hist. iii. (1839); Id. Ann. Nat. Hist. viii. and x. (1839-42); Id. "On the Geographical Distribution of the Rodentia," Proc. Zool. Soc. 1839, pp. 162-174; Id. Natural History of the Mammalia, vol. ii. "Rodentia" (1848); Gervais, Dic. Univ. d'Hist. Nat. xi. p. 202 (1848); Brandt, "Untersuchungen über die craniologischen Entwickelungsstufen und Classification der Nager der Jetzwelt," Mém. de l'Acad. Impér. de St. Pétersbourg (1855): Liljeborg, Systematisk Efversight af de Gnagnde Däggdjuren, Upsala, 1866; Alston, “On the Classification of the Order Glires," Proc. Zool. Soc. 1876, pp. 61-98; Trouessart, "Catal. de Rongeurs, Vivants et Fossiles," Bullet. Soc. d'Etudes Scient. d'Angers, 1880-81; Coues and Allen, "Monographs of North American Rodentia," United States Geol. Surv. of Territories, vol. xi. (1877); Winge, "Rodentia pa Lagos Santa, Brazil," Mus. Lund. vol. iii. (1887); various papers by Peters in Monatsber. Ak. Berlin, and by Alston, Anderson, Blanford, Dobson, Milne-Edwards, Thomas, and others, in Proc. Zool. Soc., Journ. Asiat. Soc. Beng., Ann. Mag. Nat. Hist., etc.

1 Variations of Animals and Plants, 2d ed. vol. i. p. 119.

CHAPTER XI

THE ORDER CARNIVORA

THOUGH the existing Carnivora as at present restricted1 form a very natural and well-defined order among the Mammalia, it is difficult to find any important common diagnostic characters by which they can be absolutely separated; so that, as in the case of so many other natural groups, it is by the possession of a combination of various characters that they must be distinguished. Thus they are all unguiculate, and never have less than four well-developed toes on each foot, with nails more or less pointed, rarely rudimentary or absent. The pollex and hallux are never opposable to the other digits. They are regularly diphyodont and heterodont, and their teeth are always rooted.2 Their dentition consists of small pointed incisors, usually three in number, on either side of each jaw, of which the first is always the smallest and the third the largest, the difference being most marked in the upper jaw; strong conical, pointed, recurved canines; cheek - teeth variable, but generally, especially in the anterior part of the series, more or less compressed, pointed, and trenchant; if the crowns are flat and tuberculated they are never complex or divided into lobes by deep inflexions of enamel. The condyle of the lower jaw is a transversely placed half-cylinder working in a deep glenoid fossa of corresponding form. The brain varies much in relative size and form, but the hemispheres are never destitute of well-marked convolutions (Fig. 23, p. 71). The stomach (Fig. 234) is always simple and pyriform. The cæcum is either absent or short and simple (Fig. 235), and the colon is not sacculated, or greatly wider than the small intestine. Vesiculæ seminales are never present. Cowper's glands are present

1 The Feræ of Linnæus included all the then known species of the modern orders Carnivora, Insectivora, and Marsupialia.

2 The tusks of the Walrus, altogether so aberrant in its dentition, are partial exceptions to this statement, but in old individuals the pulp-cavity fills up, and they cease to grow.

in some, absent in other groups. The uterus is bicornuate. The mammæ are abdominal, and very variable in number. The placenta is deciduate, and almost always zonary. The clavicle is often entirely absent, and when present is never complete. The humerus often has an entepicondylar foramen. The radius and ulna are distinct. The scaphoid and lunar bones are united into one, and there is never a distinct os centrale in the adult. The fibula is always a distinct slender bone.

Several of these characters are, however, not applicable to all the members of the extinct group of Carnivores for which the name Creodonta has been proposed, as will be noticed in the sequel.

The large majority of the species composing this order subsist chiefly upon some variety of animal food, though many are omnivorous, and some few chiefly, though not entirely, vegetable eaters. The more typical forms live altogether on recently-killed warm-blooded animals, and their whole organisation is thoroughly adapted to a predaceous mode of life. In conformity with this manner of obtaining their subsistence they are generally bold and savage in disposition, though some species are capable of being domesticated, and when placed under favourable circumstances for the development of such qualities exhibit a very high degree of intelligence and fidelity. The existing representatives of the order are naturally divided into two suborders, the members of the one being the more typical, and mainly terrestrial in their mode of life; while those of the other are aberrant, having the whole of their organisation specially modified for living habitually in water. These are called respectively the True, or Fissiped, and the Pinniped Carnivora.

Suborder CARNIVORA VERA.

Generally adapted for terrestrial progression and mode of life, though some may be partially aquatic in their habits. The fore limbs never have the first digit, or the hind limbs the first and fifth digits, longer than the others. Incisors on each side, with very rare exceptions. Cerebral hemispheres more or less elongated; always with three or four gyri on the outer surface forming arches above each other, the lowest surrounding the Sylvian fissure. The molar series of teeth have not the uniform characters of those of the Pinnipedia. There is always one tooth in each jaw which is specially modified, and to which the name of "sectorial" or "carnassial" tooth has been applied. The teeth in front of this are more or less sharp pointed and compressed; while those behind it are broad and tuberculated. The characters of the carnassial teeth deserve special attention, as, though fundamentally the same