. Natural history object lessons : a manual for teachers. s gums and resins; others again areperfume-factories, others colour-makers; but all the variousproducts are made from the sap elaborated first by theleaves from the elements of water, and air, and a littleearthy matter taken up from the soil. CHAPTER V. ROOTS AND THEIR FUNCTIONS. EooTS serve the double purpose of fixing the plant to thesoil, and of absorbing the food and moisture necessary to itsgrowth. It is the nature of the root todivide itself into branches and fibres, whichspread beneath the ground. If we examinethe sides and extre
. Natural history object lessons : a manual for teachers. s gums and resins; others again areperfume-factories, others colour-makers; but all the variousproducts are made from the sap elaborated first by theleaves from the elements of water, and air, and a littleearthy matter taken up from the soil. CHAPTER V. ROOTS AND THEIR FUNCTIONS. EooTS serve the double purpose of fixing the plant to thesoil, and of absorbing the food and moisture necessary to itsgrowth. It is the nature of the root todivide itself into branches and fibres, whichspread beneath the ground. If we examinethe sides and extremities of these under-ground branches, we shall find a number ofdelicate rootlets. The free ends of theserootlets are soft and spongy, and these arethe parts by which the plants mainly absorbmoisture. That roots absorb fluid very Ks. 12.—Tip ofrapidly may readily be shown by taking a ^fied^^^^^^small growing plant, and, after cleansing ofearth, immersing the roots in water. Of the water ab-sorbed, however, but a small portion is retained by the plant,. 26 NATURAL HISTORY OBJECT LESSONS. the greater part is sent out again by the leaves. This isprobably owing to the fact that the solidmineral matters, which constitute an importantpart of the food of the plant, are dissolved inthe water in very minute quantities, and to geta sufficient supply of these matters more waterhas to be absorbed than is necessary for thewants of the plant. Roots sometimes serve as winter storehousesfor nourishing matter on which the plants feedin the ensuing year. Such are the fleshy rootsof the turnip, carrot, parsnip, and raddish; andthe tuberous root of the dahlia. Other rootssupply only the present wants of the plant,that is, they absorb only. Such are theHbrous roots of trees, and bushes, and grasses. There is a close connection between the kind of root, and the duration of life in a plant. Trees and shrubs all have branching roots, which finally end in tender fibres, or rootlets. These roots are n
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