200 
ZOOLOGICAL GEOGRAPHY. 
[part hi. 
mountainous, and much of their surface considerably elevated. 
Further east we have all European Turkey and Greece, a 
mountain region with a comparatively small extent of level 
plain. In Asia the whole country, from Smyrna through 
Armenia and Persia to the further borders of Afghanistan, is a 
vast mountainous plateau, almost all above 2000, and extensive 
districts above 5000 feet in elevation. The only large tract of 
low-land is the valley of the Euphrates. There is also some 
low-land south of the Caucasus, and in Syria the valley of the 
Jordan. In North Africa the valley of the Nile and the coast 
plains of Tripoli and Algiers are almost the only exceptions to 
the more or less mountainous and plateau-like character of the 
country. Much of this extensive area is now bare and arid, 
and often even of a desert character ; a fact no doubt due, in 
great part, to the destruction of aboriginal forests. This loss 
is rendered permanent by the absence of irrigation, and, it is 
also thought, by the abundance of camels and goats, animals 
which are exceedingly injurious to woody vegetation, and are 
able to keep down the natural growth of forests. Mr. Marsh 
(whose valuable work Man and Nature gives much information 
on this subject) believes that even large portions of the African 
and Asiatic deserts would become covered with woods, and the 
climate thereby greatly improved, were they protected from 
these destructive domestic animals, which are probably not 
indigenous to the country. Spain, in proportion to its extent, 
is very barren ; Italy and European Turkey are more woody and 
luxuriant ; but it is perhaps in Asia Minor, on the range of the 
Taurus, along the shores of the Black Sea, and to the south of 
the Caucasus range, that this sub-region attains its maximum of 
luxuriance in vegetation and in animal life. From the Caspian 
eastward extends a region of arid plains and barren deserts, 
diversified by a few more fertile valleys, in which the charac- 
teristic flora and fauna of this portion of the Palsearetic region 
abounds. F urther east we come to the forests of the Hindoo 
Koosh, which probably form the limit of the sub-region. 
Beyond these we enter on the Siberian sub-region to the north, 
and on the outlying portion of the Oriental region on the south. 
