14 BRITISH PLANTS 



8. The Nature of the Soil. — ^From a purely climatic 

 point of view, the soil is not important, but ecologically 

 it is important because it forms the abode of the vegeta- 

 tion. Climate may determine in broad outlines the 

 geographical aspects of the vegetation, but the diversity 

 of the flora in particular areas is the result, not of differ- 

 ences in the climate, but of differences of interaction 

 between soil and chmate. What these interactions are 

 wiU be made plain when we have considered the properties 

 of the soil, and the relations of the various kinds of soils 

 to the available supply of heat and moisture (Chapter IX.). 



