204 
INFLUENCE OF CLIMATE ON VEGETATION. 
The construction of this table is obvious ; thus the region assigned to Alpine plants, 
which, in the Arctic zone, occupies the elevation of 1900 feet, in the tropical zone will he 
at an elevation of 11,400 feet, under the colder temperate zone at 5700 feet, and so on 
with the other regions. Meyen’s names for these regions are inserted in parentheses : 
the object of inserting the table is better accomplished by numbering the regions and 
zones, than by giving prominence to their names. So far as artificial cultivation is 
concerned, the horizontal zones of vegetation may be considered as severally identical with 
the vertical regions, according to the numbers respectively attached to each series. 
The remainder of the present paper will be appropriately occupied with some addi- 
tional particulars respecting the zones and regions indicated in the accompanying table, 
as prefatory to a scheme for dividing the surface of the earth, somewhat after Meyen’s 
plan, into regions corresponding with the series of garden structures which is assumed to 
be required for the cultivation of a full miscellaneous collection of exotic plants. The 
zones and regions will be taken in conjunction one with another. 
Zone I . — The Equatorial Zone is characterised by the high annual mean temperature 
of 80-86° Fahr., which when accompanied by a corresponding amount of moisture gives 
rise to the most luxuriant vegetation. Palmas, Musacea, arborescent grasses, Scitaminece, 
and Orchidea, are generally prevalent. The trees of the mighty forests are covered with 
splendid epiphytes, and the most elegant ferns ; whilst high among the foliage, are the 
Lorantlis, Tillandsiea, and Pitcairnia. The variation in the supply of moisture causes 
striking differences, as is seen in the deserts of Africa, the Pampas of Peru, and the 
Savannahs of the Orinoco. This zone comprises 15° of lat. on each side the equator. 
Region I . — Beginning at the sea-coast, wherever there is rich soil, Palms, Musas, and 
Scitamineae, are characteristics up to 1000 or even 1600 feet. There begin, in the New 
World, the Cereuses, and in the Old, the Cactus-like Euphorbias. With increasing 
altitudes, Palms and Scitamineae begin to disappear, but the Orchideae become more 
numerous. 
Zone II. — In the Tropical Zone we have a mean annual temperature of 74-80° Fahr. 
Here is an endless mass of arborescent Ferns. Convolvulacea, Melastomacea, and 
Piperacea, are predominant towards the limits of the torrid zone. The zone reaches 
from 15° of lat. to the tropics. Much of this tract is poor, and insufficiently supplied with 
moisture. Here we have Bio de Janeiro, the extreme south of China, India, the 
Sandwich Isles, the northern part of the Philippines, the West Indian Islands, &c. 
Region II. — The Tree-Ferns occur profusely where the climate is damp, but where the 
atmosphere is dry they are wanting. In the New World, the Melastomas are exceedingly 
abundant, and the Cinchonse are characteristic. In the South Sea Islands the family of 
TJrticece predominate in the genera Broussonetia, Artocarpus, &c. In India, and the 
Indian Archipelago, these are replaced by species of Ficus. The Ferns keep very closely 
between 1200 and 3000 or 4000 feet. 
Zone III. — From the tropics to 34° lat. The mean temperature is 65-70° Fahr. 
Meyen speaks of this zone as possessing “the happiest clime.” The Canaries, and 
Madeira occur here ; as do Southern Africa, Egypt, the western parts of India, and part 
of China and Japan. The greater part of Australia, the Cape Colony, and a small zone of 
South America occur here. The Myrtacece, Camellias, the Tea-plants, and a great 
number of succulent plants, as Sempervivum, Mesembryanthemum, dec., occur in this zone. 
The Proteacea, Eucalypti, Acacia, Erica, attain their maximum. The Cacti abound in 
sub-tropical America. 
Region III. — Myrtacea and Laurinea are the predominant forms, the latter occupying 
the greater altitude. In Chili, Myrtles occur in great numbers. In the mountains of 
Java, beautiful Conifer a appear, the Nepenthes climbing their trunks. 
Zone IV. — The warmer Temperate Zone situated from 34 to 42° lat. In Europe it 
includes all the southern part, as far as the Pyrenees, the mountains of the south of 
France, and of the north of Greece. Asia Minor, the tract between the Black Sea and 
the Caspian, the northern part of China and Japan, all lie in this zone. The flora of the 
north of Africa has quite the aspect of that of the extreme south of Europe. This zone 
