CLIMATE AND PLANT-LIFE. 
101 
with what will form plant-food. It also helps to 
keep the soil in good order, by causing a stiff soil 
to lie loose and open to the air, and by binding 
together one that is loose and sandy, so that it 
becomes able to hold sufficient moisture. 
CLIMATE AND PLANT-LIFE. 
1 . To one who visits the shores of many countries, 
as a sailor does, perhaps nothing appears more 
remarkable than the great variety in the kinds of 
plants in different parts of the world. He may see 
the hardy pine forests in the North of Europe, the 
fields of wheat in Canada, of rice in India, and of 
corn or tobacco in the United States. 
2 . In the warmth and moisture of the West 
Indies, and other tropical lands, he may see how 
magnificent plant-life can become; while in very 
cold regions of the earth a few mosses and lichens 
are all the vegetation he can find. 
3. Again, if a traveller ascends a high mountain in 
the tropics, he will pass through varying groups of 
vegetation, just as he would in a journey from the 
Equator to countries in the extreme north or south. 
4. These great differences are not so much owing 
to soil, which man can to some extent improve, as 
to climate, over which man has no control. 
5. You must have noticed, even in our little 
