NORTHERN ASIA.—QUADRUPEDS. 45 
and the eastern shores of the Caspian ; while to the 
south, the stupendous Himalayan mountains seem to 
form a natural boundary to this intermediate region. 
The third division comprehends the remaining portion 
uf the continent, together with Java, Sumatra, &c., and 
such islands as lie to the westward of New Guinea. 
We thus exclude the whole of Asia Minor, and the 
regions immediately around Caucasus, because they ex- 
hibit a zoology of no determinate character, further than 
as they present a union of the European, Asiatic, and 
African ; thus concentrating much of the typical cha- 
racters of the whole. ‘The same observation, in a more 
limited sense, may be extended to Persia ; but there the 
African forms almost entirely disappear, and leave only 
the European and the Asiatic — the latter evidently 
preponderating. 
(62.) The first, or northern Asiatic range, exhibits 
few peculiarities: the genera of quadrupeds, for the 
most part, assimilate to those of Europe and the North 
Pole, but few of the species occur on the western side 
of the Ural mountains. The sandy and desert steppes 
of Siberia afford but little nourishment to large animals, 
but are sufficient to support many of the Glires family : 
hence the chief quadrupeds enumerated by travellers as 
natives, are nearly all referred to the field mice (Ar- 
vicola), lemmings (Georynchus), rats (Mus), and 
hamsters (Cricetus). These generic groups, for the 
most part, are restricted to the cold or temperate lati- 
tudes of Europe, Asia, and America. The field mice 
(Arvicola) and the true mice (Mus) occur also in 
Africa. These gnawing animals, however, have a very 
wide distribution, and have obviously been intended by 
nature to inhabit climates subject to the severities of 
winter. The instinct by which they are impelled to 
hoard up large quantities of provisions against the season 
of scarcity ; the length, intricacy, and warmth of their 
subterraneous abodes ; their food, of dried grass, seeds, 
er nuts, in winter, and of green or fresh vegetables in 
summer ; are all proofs to this effect. We acc.rdingly 
