II. THE KOOT. 31 



partly water, mixed with some kinds of air (ammonia, etc.,) 

 but the plant can get both water and ammonia from the 

 atmosphere ; and, 1 believe, for the most part does so ; 

 though, when it cannot get water from the air, it will 

 gladly drink by its roots. But the things it cannot receive 

 from the air at all are certain earthy salts, essential to it 

 (as iron is essential in our own blood), and of which when 

 it has quite exhausted the earth, no more such plants can 

 grow in that ground. On this subject you will find enough 

 in any modern treatise on agriculture ; all that I want you 

 to note here is that this feeding function of the root is of 

 a very delicate and discriminating kind, needing much 

 searching and mining among the dust, to find what it 

 wants. If it only wanted water, it could get most of that 

 by spreading in mere soft senseless limbs, like sponge, as 

 far, and as far down, as it could but to get the salt out 

 of the earth it has to sift all the earth, and taste and touch 

 every grain of it that it can, with fine fibres. And there- 

 fore a root is not at all a merely passive sponge or absorb- 

 ing thing, but an infinitely subtle tongue, or tasting and 

 eating thing. That is why it is always so fibrous and di- 

 vided and entangled in the clinging earth. 



9. " Always fibrous and divided " ? But many roots 

 are quite hard and solid ! 



No ; the active part of the root is always, I believe, a 

 fibre. But there is often a provident and passive part a 

 savings bank of root in which nourishment is laid up for 

 the plant, and which, though it may be underground, is no 



