18 



INTRODUCTION. 



leaves. The root fastens it firmly in the ground ; 

 the rootlets take up liquids from the soil; the stem, 

 branches, and branchlets are furnished with vessels 

 and passages through which the fluids find their way 

 to the leaves, where, under the influence of air and 



(7, Quercus alba. 



sunlight, they are changed and fitted for plant 

 food. 



37. The next stage in the plant's life is the produc- 

 tion of the flower. To accomplish this, a change takes 

 place in the mode of development. Some of the buds, 

 instead of extending the axes of the branchlets or 

 forming new branchlets, expand their scales, producing 



