160 Chapters in Modern Botany CHAP. vm. 



short, they live and grow, should be enough to convince us 

 that they must feed in some way, no less than animals. In our 

 study of insectivorous plants we saw some strange examples 

 of feeding, and in chap, iv., in considering the plant not as 

 an isolated thing, but as part of the great system of nature, 

 we got glimpses of some of the ordinary relations of plants 

 to the air, to the soil, and to radiant energy. Let us seek 

 to get a more precise conception of these relations, let us 

 see how the important parts of a plant leaves, roots, and 

 stem are adapted to the sustenance of the life. Let us 

 look closely at these different parts, and see how their 

 forms are suited to, and modelled partly by, the uses which 

 they have to perform, partly by the surrounding conditions 

 in which they live : in technical language, let us consider 

 the adaptation of plant-structure to function and environ- 

 ment. For this we can have no better type than is given 

 by a fuller study of the leaf, to which we may therefore 

 turn. 



