THE PREPARATION FOR WINTER 



evident that much surplus water is taken into the plant. This 

 water aids in the circulation of foods in the plant. All that is not 

 needed is evaporated from the leaves into the air. This process 

 is called transpiration of water. This takes place through the 

 little mouths or stomates which are so abundant on the lower 

 surfaces of leaves. 



Importance of Leaves. — The great importance of the leaf 

 growth on all our common leaf-bearing plants may be understood 

 when we realize that (1) the leaves make the starches, sugars, and 

 similar products for the plants, constituting about ninety-five per 

 cent of the food of the plant. (2) It is through the leaves that the 

 necessary breathing takes place. (Fig. 5.) 

 (3) The leaves give off to the air the surplus 

 water no longer needed by the plant. 



The increasing of leaf growth which is to 

 accomplish all of these purposes, is often the 

 main efforts of the orchardist and gardener. 

 The use of manure and nitrogenous fertilizers 

 aids in the leaf growth. Leaf-eating insects 

 must be kept in control to prevent the de- 

 struction of leaves. Pruning may direct the 

 growth in the best parts of the plant. 



Bud Formation. — On all plants the leaves 

 are formed from the unfolding of buds. On 

 the woody plants the buds are formed chiefly 

 in the angles of leaves. They form on the new 

 growth of shoots in spring and early summer, 

 soon after the leaves of that year are well de- 

 veloped. They become more plump later in the year, and really 

 prepare for winter during the last half of the summer season. 



The preparation for winter of fruit trees and other woody plants, 

 usually consists of all or nearly all of the following processes: (1) 

 Buds are formed and covered with winter scales for protection 

 from changes of weather. (2) Hairy or waxy growth is provided 

 to keep out water and ice. (3) In the fall the leaves drop off and 

 the leaf scars are sealed with a corky growth. (4) The green parts 

 of the twigs form thicker bark. (5) The breathing pores on the 

 twigs become closed with corky growth called lenticle spots. (6) 

 The buds and twigs become drier by the retreat of sap. (7) The 

 starch and other forms of stored plant-food become fixed in the 

 buds, pith, and elsewhere. 



Fig. 5. — Aself -sustaining 

 aquarium; balanced with 

 plants to supply oxygen 

 and water animals to sup- 

 ply carbon dioxide. 



