STORAGE OF FOOD AT 
leaves. The Lettuce is another plant which utilises its 
leaves as a place of storage for food. 
Storage in Stems. Then again we have already seen 
that a food supply is stored up by the Potato in its tubers, 
and by such plants as the Onion and Lily in their bulbs. In 
the case of the Dahlia, the tuberous bodies in which the food 
is stored arise on the base of the stem, and possess neither 
leaves nor buds, they are in fact true roots. 
Summary of Lessons on Roots. The work already 
done might now be summarised, or a lesson might be given 
to a junior class on roots, when the following could be educed : 
(1) The root serves to hold the plant firmly in the ground. 
Pupils can readily be brought to see that the vertical 
position of plants requires them to be firmly set in the soil ; 
with this object some roots spread themselves out far and 
wide, and penetrate to considerable depths. Reference 
can be made in this connection to large forest trees, and 
comparisons drawn between plants requiring a firm hold 
and those whose height above ground and weight do not 
cause any great strain on the root, such plants being 
easily removed from the soil. 
(2) The root enables a plant to obtain a supply of 
food from the soil. This can be illustrated by some of 
the experiments already described, the precise nature of 
these depending on the intelligence of the pupils. 
(3) The root serves as a storage place for food, ¢.9., root 
of Carrot, Parsnip, Turnip. 
The Shape and Colour of Roots. This will fur- 
nish subject matter for a useful lesson to a class of 
beginners. The pupils may be called on to describe the 
colour and shape of a few typical roots, and, at the close 
of the lesson, to draw the forms examined and described. 
The following would serve as a basis for such a lesson. 
