116 THE NATURE AND WOEK OF PLANTS 



capable of great multiplication of cells and growth. 

 At certain points this tissue has acquired the power 

 of forming new branches, flowers, and leaves, hence 

 it is called embryonic tissue. These specialized 

 masses of cells are generally in the form of minute 

 outgrowths, and are located at the tips of the stem 

 and its branches as well as in the axils of the 

 leaves. This tissue is most delicate and easily in- 

 jured, and is generally protected by coverings of 

 leaves or bracts. The growing points or masses of 

 embryonic cells and their coverings form buds. 



159. Naked buds. In species growing in tropi- 

 cal and mild climates the buds are only slightly 

 shielded by the young leaves near the tip of the 

 stem, and no special coverings are developed. Such 

 an arrangement is called a naked bud, and an ex- 

 ample may be seen in the cultivated geranium or 

 pelargonium. 



160. Scaly buds. Plants which grow in cold 

 or dry climates generally adopt some method of 

 protecting the growing points from damage. The 

 most common device is a number of wrappings of 

 brownish scales, which are in reality a special form 

 of leaves which are used for protection instead of 



