340 Journal of Agriculture, Victoria. [11 June, 1917. 



cell tissue. The growing points of these yoting roots or food seekers 

 have to advance through the soil by forcing their way through its pores 

 or interspaces. 



The continuous cellular multiplication which takes place at its 

 feeding point enables the root, under the protection of a membraneous 

 covering-sheath or root-cap, to force its way through the soil in the 

 manner described. 



Plate 91, Fig. 1, shows a highly-enlarged longitudinal section of the 

 point of a feeding root of the Northern Spy variety, the root-cap of 

 which was removed during the process of mounting prior to the speci- 

 men being photographed. The rounded cells at the growing point are 

 visible, as is the vascular tissue composed of elongated cells which run 

 longitudinally. Fig. 1 (a) is the natural size of this section. Fig. 2 



Plate 97. — Leaf of the Prince Alfred variety from which moisture and 

 chlorophyll have been removed. 



is a cross section of a similar root. It clearly depicts the cell formation, 

 pith, &c., and was taken from the root at the point (b) Fig. 1. Fig. 2 

 (a) is the natural size of this section. 



The feeding root, as it passes through the soil, absorbs in the state 

 of solution by the process of osmosis the various elements which enter 

 into the tree's food. Amongst the principal constituents are sulphur, 

 phosphorus, silicon, lime, potash, soda, &c. Nitrogen is also taken in 

 by the roots for, although there are large quantities in the air, it cannot 

 be absorbed by the leaves. 



As well as taking in by osmosis the sap food required to build up 

 the tree, certain cell sap in the form of acid is given out by the root. 

 The object of giving out this acid is to dissolve certain earthy matters 

 which the tree requires as food, but which are insoluble in soil water 

 in the ordinary way. The elaborated sap in the tree contains carbon, 



