378 POPULAB BCIENCE REVIEW. 
thirsty land, and vegetation springs up with almost miraculous rapidity, 
and “ the dull tawny surface of the parched Savannah changes as if by 
magic into a carpet of the most lively green, enamelled with thousands of 
flowers of every colour.” The Puna, or uninhabited region of high table- 
lands in Peru and Bolivia, though situated near the Llanos, in the torrid 
zone, yet being elevated from 10,000 to 14,000 feet above the sea, contrast 
with them in their bleak and unfriendly climate, constantly liable to wintry 
storms and sudden changes of temperature, as much as 45° in a few hours. 
In such unfriendly regions a few stunted shrubs and dense grass form the 
characteristic vegetation ; and from these the useful llama and alpaca 
derive subsistence, the wool which protects them from the inclemency of 
the situation being one of their chief attractions. In Africa, the Kalahari 
and the Sahara — though both deserts — are not both equally inhospitable ; 
for while Sahara, extending from the 39th to the 70th degree of N. lati- 
tude, is a dreary waste, redeemed only by bright green oases, which break 
its monotony, like the charming islands which stud the vast solitudes of 
the Pacific, the Kalahari is far from being destitute of animal and vege- 
table life. It contains but little water, but in no other respect can it be 
called desert, being covered with grass and creeping plants, while the 
Caffre water-melon covers the ground in some seasons with juicy gourds. 
Koodoos, gemsbocks, elands, and other antelopes may often be seen here 
forty miles from the nearest water ; and other game, such as rhinoceri, 
buffalos, gnus, and giraffes are not unfrequent in its immediate neighbour- 
hood. To each of these characteristic regions, as well as to the Peruvian 
sand-coast, the Mexican plateaux, the mighty Amazons, in the West, and 
the Sikkim slopes and mangrove swamps in the East, is an interesting- 
chapter devoted in the work before us. 
The characteristic forms of tropical vegetation consist of trees often of 
gigantic size, such as the baobab, or Adansonia, more than a hundred feet 
in circumference, though only about sixty feet high ; great dragon trees 
( Dracaenas ), sycamores, and the widely-renowned banyan ( Ficus indica ), 
each tree a little grove, sending out in the case of a celebrated one on the 
banks of the Nerbuddah 3,000 root-trunks, still covering a space of ground 
2.000 feet in circumference, and once known to have afforded shelter to 
7.000 men. Often to beauty of foliage and majesty of form there is super- 
added a delicious aroma, as in the sandal-tree of the Malabar coast ; or the 
attention is arrested by a strange grotesqueness of form, as in the giant 
cacti of the New World, some remarkable specimens of which are figured 
in Plate 4, rising in angular columns to the height of 60 feet, generally 
branchless, sometimes strangely ramified as candelabras, while others 
creep like ropes upon the ground, or hang snake-like from the trees. In 
similar situations to the last are “ endless varieties of epiphytal plants of 
inconceivable size and luxuriance, such as ferns, bromelias, tillandsias, or- 
chids, and pothos, covering the trunks and branches of the forest trees with 
hanging gardens far more splendid than those of ancient Babylon.” But 
the palms must not be forgotten — the trees of all others the benefactors of 
man — whose three hundred and sixty uses have been sung by the Eastern 
poets. “ Some years ago a ship from the Maidive Islands touched at Galle, 
which was entirely built, rigged, provisioned, and laden with the produce 
