An experienced cultivator can generally judge by a superficial examination, aided by the situation, locality, and appearance of the soil, whether a certain portion of land is fitted for the profitable growth of any particular plant.  Depth of soil, and facilities for deepening it, with the nature of the subsoil, so as to know whether it retains or parts with water, are also important considerations, because tap-rooted plants require free scope for penetrating deep into the ground.

A due supply of water is of vital importance to most crops—­and therefore the extent and periods of the fall of rain are essential to be known, as it is not always possible to resort to irrigation.  The quantity of labor required for previous tillage, cultivation, and harvesting of different crops, and the available supply, are primary essentials to be considered before entering upon the culture of any staple product, however remunerative it may appear in prospective.  Facility and cost of transport to the nearest market or shipping port are the next desiderata to be ascertained, as well as a careful estimate of the cost of plant or machinery necessary.

It may be desirable at the outset to make a brief enumeration of the countries lying within the different zones, and the agricultural products of which come, therefore, more especially under the notice of the tropical planter.

Meyen, in his division of the horizontal range of vegetation into zones, extends—­

1.  The equatorial zone to fifteen degrees on both sides of the equator.  In this division we shall find the Cape Verd Islands, Sierra Leone, Ascension, and St. Helena, the Republic of Liberia, the European and native settlements in the Gulf of Guinea, and on the western Coast of Africa, Abyssinnia, Zanzibar on the East Coast, Mocha and Aden in the Red Sea, the northern portion of Madagascar, the Seychelles, the Madras Presidency, Northern India, Ceylon and the Nicobar Islands, Sumatra, Siam, Malacca, Singapore and the Straits Settlements, Cochin China, the Phillippine Islands, Borneo, Celebes and the Moluccas, Java and Madura, Banca, the Johore Archipelago, Timor and the eastern group of Islands, with New Guinea, a large portion of Northern Australia, the Marquesas, Society’s and other oceanic islands.  In South America the Republics of Peru, Bolivia, Ecuador, New Granada, and Venezuela, British, French and Dutch Guiana, and a large portion of the empire of Brazil; Trinidad, Barbados, and most of the islands in the Carribean Sea.

This zone has a mean temperature of 781/2 to 821/2 Fahrenheit.

2.  The tropical zone reaches from the 15th deg. on each side of the equator to the tropics in 23 lat.  The mean temperature is 731/2 to 783/4 deg.  Summer temperature 801/2 to 86 deg.; winter temperature in the eastern coast districts, 59 deg.

In this region is comprised the following countries:—­Sandwich Isles, Canton, in province of China, Burmah, Calcutta, and a portion of the Bengal Presidency, the Bombay Presidency, Madagascar, Mauritius and Bourbon; the southern portion of Brazil, Cuba, St. Domingo, Mexico, and Central America.