382 
the area of a plant. Thus Vanilla a crop of considerable value with 
a limited source of supply, is not successfully grown here because 
although the growth of the plant is rapid and easy, it flowers 
regularly and well, and appears to have no enemies, it fails from the 
fact that the slowly ripening fruit requires nearly four months dry 
weather in order to mature. . If during this period a heavy spell of 
rain falls, the young fruits perish, and as the plant flowers at a period 
just preceding the wetter months here, the fruit crop usually fails. 
An ideal plant for the planter is one belonging to the class of 
those in constant everyday use, which can only be grown in a 
limited area. Now if the areas of successful cultivation of this class 
of crop be as carefully studied as we have data for, we shall see a 
great difference in the values of the cultivations as studied from 
this point of view. 
I may say, it is not very easy to judge accurately the amount of 
suitable area for any given cultivation even approximately, in spite 
of all reports and agricultural publications published all over the 
world. There is a great tendency to exaggerate the area which 
can be used. Some one for instance, reports surprising growth of a 
rubber tree or trees in some region and prophesies a great future 
for the. cultivation. A few years go by and one hears no more. 
Enquiries show that the opinion was based on a few trees in very 
special almost horticultural circumstances, and that the area is 
utterly unsuitable for the plant. 
As far as tropical cultivations are concerned we may take approxi- 
mately 20 degrees North and 20 South of the line in which we can 
grow tropical plants vrith anything approaching success. This area 
includes the Northern part of Australia, the Malay Peninsula and 
» Islands, Cochin-China, India south of Calcutta, a large area of 
Africa, and America from Mexico and the West Indies to Rio de 
Janeiro and a considerable number of Polynesian Islands. Now 
taking our chief tropical crops of the first class, we see that Coffee 
can be grown over almost every portion of thfsarea excluding per- 
haps the desert portions of Australia, Africa and a small area in 
South America. 
Tea again has been successfully grown, over the greater part of 
the same area and further North in some parts of Asia. That it has 
not been grown in South America is due to the required supply 
being produced in Asia, and from the fact that it has never had any 
market to speak of in South America. To a certain extent these 
two products supplement each other; and when one is used the 
other is not. 
Sugar again is one of tne plants of which though the demand is 
very large the area of cultivation is of very large dimensions, extend- 
ing not only over most of the tropical regions but also over an 
extensive temperate region. 
