ROOTS OF PLANTS. 



430 



ROOTS OF PLANTS. 



If the tree is extremely vigorous, without 

 producing fruit, two-thirds of the stronger 

 roots cut through in this manner will pro- 

 bably restore it to a state of perfect bearing ; 

 the trench being filled up with fresh virgin 

 mould, and the tree left at rest for a year. 

 The proper season for root-pruning is the 

 autumn, when the roots will send forth 

 small fibrous spongioles. which elaborate 

 the sap, and lorm inossom-buds. Should 

 this operation fail to check the superfluous 

 vigour of the tree, the roots may be again 

 laid bare in the following autumn, and the- 

 remaining large roots then cut away, avoid- 

 ing, as much as possible, all injury to the 

 smaller fibres which have pushed out from 

 the previous operation. Should the tree 

 still present an over vigorous growth, it 

 must be taken up entirely, and all the 

 strong roots pruned in, then replanted, 

 taking care that in replanting the tree is 

 raised considerably above its former level 

 a severe operation, but certain to be suc- 

 cessful in reducing the tree to a fruitful state. 



Roots of Plants : What they are. 



With regard to the root of a plant, it 

 must be remembered that it is not always 

 the portion of the plant that happens to 

 grow underground that is really its root. 

 We are accustomed to call potatoes, par- 

 snips, carrots, onions, beetroots, &c., root- 

 crops, because the parts of them that we 

 eat grow under the earth's surface, or nearly 

 so, but in reality the parts of the potato 

 that we use as food are tubers ; the carrot, 

 parsnip, and beetroot, as well as the dahlia, 

 are tuberous roots ; and the onion, in 

 common with the lily and the hyacinth, is 

 a bulb. What, then, is the root? The 

 root or roots of a plant are offsets from that 

 portion of the plant which is below the 

 earth's surface, in the form of threads or 

 filaments, terminating in soft little organs 

 called spongioles, through which moisture 

 and the various elements that combine to 



form the structure of the plant are absorbed 

 from the earth. In the case of the tree, as 

 the plumule develops into the hard stem, 

 so the radicle branches into roots, which 

 ultimately assume the form of subterranean 

 branches, that afford safe anchorage to the 

 tree itself, but at the extremities of these, 

 and at the ends of branchlets which issue 

 from them, are bunches of fibrous roots 

 terminating in spongioles, through which 

 the nourishment of the tree is derived from 

 the earth, to be carried upward to the 

 extremities by the branches that we famili- 

 arly call roots below ground, through the 

 stem and branches above ground. 



Similarly in the onion and all bulbs, the 

 roots are not the bulbous portions which 

 are produced and matured below the 

 surface of the soil, but the coronal of 

 fibres which issue from the edges of the 

 circular patch at the bottom of the bulb. 

 In the potato, the tuber, rich in starch and 

 nutritive matter, is not the root, but the 

 fleshy string-like fibre issuing from the 

 tuber, through which the food stored up 

 within it has been gathered from the soil 

 by means of the fibrous roots. The junc- 

 tion of the old root with the tuber may be 

 readily distinguished on an examination of 

 any tuber, for it differs from the eye in 

 exhibiting no signs of vitality. It will be 

 understood that this fleshy string-like fibre 

 of which mention has just been made is 

 the emanation from the root proper at the 

 end of which the tuber has taken its origin, 

 and that it acts as a medium of connection 

 between the root and the tuber, and a 

 channel for the conveyance of nutriment 

 from the soil through the roots to the 

 latter. Again, the real roots of the par- 

 snip, the carrot, and the beetroot are the 

 thread-like fibres which issue from the 

 fleshy tuberous root on all sides, and 

 especially at the extremity of the tuberous 

 toot, which is commonly stalled the tap 

 root. 



