TROPICAL EXPLOITATION 79 
rubber a few years ago, which caused the great boom 
in planting rubber in Asia, and made the merchants of 
Para and Manaos think that the millennium had arrived. 
Extravagant ways of dealing grew up, and now that the 
pinch has come it is, as usual, found that it is a good 
deal easier to increase expenditure than to reduce it. 
There is no reason to doubt, however, that reduction 
is steadily going on. 
We have now surveyed in a very brief and superficial 
way some of the enormous field of tropical exploitation, 
the object being not so much to give actual facts as to 
illustrate the underlying principles that are operative 
in tropical, as in other, agricultural progress. The 
same principles rule everywhere, and it will be well, 
before going any further, to recapitulate them. In the 
first place, we must have land available—that is to say, 
it must not be merely land, it must be clear of forest 
or other growth, it must be drained enough for the 
purpose, and if needful it must be irrigable, or have 
water available. We must also have crops which will 
grow upon that land, and whose produce can be used 
by the cultivator. The next stage begins with the pro- 
vision of means of transport, by which the cultivator, 
instead of using all that he grows, may sell some of it 
elsewhere (or barter it), and obtain other things with 
the proceeds. This in itself does not mean any great 
advance till the next factor—capital—comes into opera- 
tion, and enables a man to have a larger area, to culti- 
vate with hired labour, and to wait for his return till the 
crop can be sent to a distant market for sale. Capital 
without labour can of itself lead to nothing. We thus 
have, as the conditions for successful exploitation, as 
