120 • COCONUT PLANTER'S MANUAL. 



in length and these again sometimes give off still tinier shoots, the num- 

 ber and extent of these sub-divisions being greater in firm soil than 

 in light sands. 



The construction of all these roots is the same. On the outside is 

 a hard and rigid shell, called the hypodermis, whilst down the centre 

 of every root runs an exceedingly strong pith in the form of a cable. The 

 rigid hypodernr.s is admirably suited to withstand a bending strain.: whilst 

 the cable-like pith will resist an immense tension. These two devices, 

 in conjunction with the fact that all sub-divisions of the roots grow 

 out at wide angles to the branch which bears them, constitute a most 

 perfect form of anchorage which enables the palm to stand up against 

 the fiercest storms to which it may be subjected. 



So much for the mechanical functions performed by the roots : now 

 for that which is concerned with the absorption of nitrogen and mineral 

 plant foods. 



The outstanding difference between the roots of the coconut palm 

 and those of other crops is that the former bear no root-hairs. At the 

 extremity of each sub-division of the roots of the coconut palm is a dark 

 coloured conical object known as a " root cap " which is composed of 

 tough woody fibres and is for the purpose of protecting the tender 

 growth-point of the root as it forces its way through the soil. Imme- 

 diately behind the root cap, for a distance of not more than two inches 

 in the case of the main roots and of only a fraction of an inch in the 

 case of the root-branches, is an area of soft tissue through which the 

 plant-food is absorbed. Behind this area of soft tissue- and right back 

 to the base of the palm the long strands of roots are sheathed in their 

 casing of hypodermis which is quite impervious to weather. At fre- 

 quent intervals along the root-strands are found curious small white 

 projections which are special breathing organs for the purpose of ad- 

 mitting air into the roots, but no plant-food whatever can gain entrance 

 to the palm except through the soft-walled tissue at the extremity of 

 each main strand and of each sub-division. 



These facts relating to the structure and growth of the roots of the 

 coconut palm are of the utmost importance to us when we come to con- 

 sider the questions of cultivation and manuring. 



In Ceylon the most usual number of palms grown per acre is in the 

 ncighbourhoou of seventy, that is to say the palms are about twenty- 

 four feet apart. Now from the fact that the roots of each palm extend 

 outwards for a distance of fifteen to twenty-five feet it follows that the 

 entire area of the soil of an estate of full-grown palms is enmeshed in a 

 network of roots. And from the fact that the primary roots give off 

 secondary ami tertiary branches at some distance from the parent palm 



