32 



HOW PLANTS GEOW YEAR AFTER YEAK. 



torn of each leaf, which is enlarged or thickened for containing it. These thick 

 leaf-bases, or scales, crowded together, make up the bulb ; all but its very short stem, 

 concealed within, which bears these scales above, and sends down the roots from 

 underneath. Fig. 67 shows one of the leaves of the season, taken 

 off, with its base cut across, that the thickness may be seen. After 

 having done its work, the blade dies off, leaving the thick base as 

 a bulb-scale. Every year one or more buds in the centre of the 

 bulb grow, feeding on the food laid up in the scales, and making 

 the stalk of the season, which bears the flowers, as in Fig. 1, 2. 



78. An Onion is like a Lily-bulb, only each scale or leaf-base 

 is so wide that it enwraps all within, making coat after coat. 



Bulb and lower Leaves of a Lily. 



Leaf, lowerenti culot?. 



79. In shrubs and trees a gi'eat quantity of nourii-hment, made the summer 

 before, is stored up in the young wood and bark of the shoots, the trunk, and the 

 roots. Upon this the buds feed the next spring ; and this enables them to develop 

 vigorously, and clothe the naked branches with foliage in a few days ; or with blos- 

 soms immediately following, as in the Horseohestnut ; or with blossoms and foliage 

 together, as in Sugar Maple ; or with blossoms before the leaves appear, as in Red 

 Maples and Elms. The rich mucilage of the bark of Slippery Elm, and the sweet 

 spring sap of Maple-trees, belong to this store, deposited in the wood the previous 

 summer, and in spring dissolved and rapidly drawn into the buds, to supply the early 

 and sudden leafing and blossoming. 



80. In considering plants, as to " how they grow," it should be noticed that all of 

 them, from the Lily of the field to the tree of the forest, teach the same lesson of 

 industry and provident preparation. No great result is attained without effort, and 



