THE LEAF 69 



looks almost like cotton-wool. It is in fact an ideal 

 arrangement for protecting the young leaves from the 

 cold and wet. The cotton-wool-like material keeps the 

 leaves warm, and the overlapping scales, fastened to- 

 gether by the sticky liquid, make a waterproof covering. 



On a warm day in early spring the sticky material 

 melts, and the buds glisten in the sunshine. If the warm 

 weather continues, the scales are thrust apart and the 

 tender green leaves come out and give the well-known 

 green flush of spring to the whole tree. 



How real the protection the buds afford to the 

 young leaves and flowers is well shown by the great 

 damage done, if a spell of warm weather sufficient to 

 make some of the buds open is followed by frosts. 

 It is the opened buds then which suffer; those which 

 remained closed being quite uninjured by the frost 



We have already seen in the iris and crocus the dry 

 scale leaves wrapping over the underground buds, and 

 that when these buds grow into leafy shoots these scale 

 leaves wither away. In other plants underground leaves 

 are found, which act as storehouses of food. The common 

 garden lilies, such as the tiger and white lilies, or an 

 onion, serve as good examples; and on digging up one 

 of their bulbs with the above-ground leaves still attached, 

 it will be readily seen that the thick, fleshy structures 

 which make up the greater part of the bulb, are really 

 only the thickened bases of leaves, and are of use to 

 contain starch and other food-reserves. That is to say, 

 we find leaves in these plants performing exactly the 

 same duties which the stem does in the iris, crocus, and 

 potato, and the root in the radish, turnip and beet 



