II. THE root. 43 



many things which are like roots, yet are not, you 

 may simplify and make fast your true idea of a root 

 as a fibre or group of fibres, which fixes, animates, 

 and partly feeds the leaf. Then practically, as you 

 examine plants in detail, ask first respecting them : 

 What kind of root have they ? Is it large or 

 small in proportion to their bulk, and why is it 

 so ? What soil does it like, and what properties 

 does it acquire from it ? The endeavour to answer 

 these questions will soon lead you to a rational 

 inquiry into the plant's history. You will first 

 ascertain what rock or earth it delights in, and what 

 climate and circumstances ; then you will see how 

 its root is fitted to sustain it mechanically under 

 given pressures and violences, and to find for it 

 the necessary sustenance under given difficulties of 

 famine or drought. Lastly you will consider what 

 chemical actions appear to be going on in the root, 

 or its store ; what processes there are, and elements, 

 which give pungency to the radish, flavour to the 

 onion, or sweetness to the liquorice ; and of what 

 service each root may be made capable under culti- 

 vation, and by proper subsequent treatment, either 

 to animals or men. 



1 8. I shall not attempt to do any of this for you ; 

 I assume, in giving this advice, that you wish to 

 pursue the science of botany as your chief study ; I 



