CHAPTER V 
ROOTS 
63. General character. The root is a third prominent 
plant organ, and it presents even a greater variety of rela- 
tions than leaf or stem. In whatever relation it is found 
it is either an absorbent organ or a holdfast, and very often 
both. For such work no light-relation is necessary, as in 
the case of foliage leaves ; and there is no leaf-relation, as 
in the case of stems. Roots related to the soil may be 
taken as an illustration. 
It is evident that a soil root anchors the plant in the 
soil, and also absorbs water from the soil. If absorption is 
considered, it is further evident that the amount of it will 
depend in some measure upon the amount of surface which 
the roots expose to the soil. We have already noticed that 
the foliage leaf has the same problem of exposure, and it 
solves it by becoming an expanded organ. The question 
may be fairly asked, therefore, why are not roots expanded 
organs ? The receiving of rays of light, and the absorbing 
of water are very different in their demands. In the former 
case a flat surface is demanded, in the latter tubular pro- 
cesses. The increase of surface in the root, therefore, is 
obtained not by expanding the organ, but by multiplying 
it. Besides, to obtain the soil water the roots must burrow 
in every direction, and must send out their delicate thread- 
like branches to come in contact with as much soil as pos- 
sible. Furthermore, in soil roots absorption is not the only 
thing to consider, for the roots act as holdfasts and must 
grapple the soil. This is certainly done far more effectively 
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