10 GEOGRAPHICAL DISTRIBUTION OF PLANTS, ETO. 
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from several of our most eminent scientific men. Nor is this surprising, 
when we consider the many points of the greatest interest, whether to 
the geographer, geologist, or others, which are brought under considera- 
tion, and how much light is thrown upon the history of the changes 
which have passed over our globe. After reviewing the various authors 
who have been most instrumental in ascertaining and explaining the 
various facts which have been observed, he continued that time would 
not permit his entering upon minute details, but proposed confining his 
remarks to a sketch of the most characteristic features of distribution, 
the reasons for which he would not touch upon, as, however ingenious 
and even probable might be the hypotheses which had been suggested as 
explanations, the majority of them were incapable of proof. From a 
zoological point of view, the great divisions of the world were as follows: 
—I. Palearctic, divided into four sub-regions: (1) Huropean, (2) 
Mediterranean or Mediterraneo-Persic, (3) Siberian, and (4)° Mant- 
churian or Mongolian. The boundaries of each of the foregoing and 
following regions were defined, it being especially noticed that deserts 
and seas form the most natural ones; Il. Ethiopian region, subdivided 
into (1) East African, (2) West African, (3) South African, and (4) 
Madagascar; III. Oriental region, subdivided into (1) Indian, (2) 
Ceylonese, (3) Indo-Chinese or Himalayo-Chinese, and (4) Indo-Malay 
or Malay; IV. Australian, subdivided into (1) Austro-Malayan, (2) 
Australian, (3) Polynesian, (4) New Zealand; V. Neotropical, sub- 
divided into (1) Chilian, (2) Brazilian, (3) Mexican, and (4) 
Antillean; VI. Nearctic, subdivided into (1) Californian, (2) Rocky 
Mountains and Plains, (3) Alleghanies and Eastern United States, and 
(4) Canada. The foregoing divisions are made more upon zoological 
than botanical considerations, but in the main apply to both. The 
Paleearctic region, though of immense extent, does not contain through- 
out its northern and largest portion anything approaching to the same 
variety or number of species that are found in other regions of much 
less extent. Warblers, buntings, thrushes, grouse, waders, and water- 
fowl, are the most abundant and conspicuous families of birds. Deer, 
wild goats, sheep, and rodents, are the most characteristic animals. 
Coniferee and hard-wooded timber trees, fruit trees, and herbaceous 
plants and grasses, are the most remarkable and useful among the 
vegetable forms. About 900 species of birds only are found in the entire 
region, of which not more than 200 or 250 at the most are resident in 
any oue district; but we see in the Himalayas, and in some parts of 
Central and South America 600 or 700 species existing within a radius of fifty 
miles. Insects, butterflies, and beetles, are fairly represented; but in 
Europe these appear to increase in numbers and variety as we proceed 
from N.W. to §.E. In the Mediterranean, the number and variety of 
the plants become proportionately much greater, especially in the bulbous 
forms. The Mantchurian sub-region is characterised by the presence of 
many remarkable forms, as the wild camel on the steppes of the N.W. 
Tibet, and the yak, the saiga antelope, the great wild sheep of the Pamir 
plateau, and among birds especially by the pheasants. Its flora (except 
on the coast of China and Japan) is marked by the absence rather than 
the presence of peculiar or remarkable plants; that of the plateaus and 
ty 
