BUDS AND LEAVES. 23 



tion have increased their cellular integument, and thereby, 

 from being totally worthless, have become food for man and 

 beast. The bark seems to perform several functions, as 

 the protection of the new wood, forming a channel for the 

 descending elaborated sap, and for the secretion of various 

 products, such as cinchona in the Peruvian bark, tannin 

 in the oak, and what is more familiar to you, sweet-gum in 

 the liquid-amber or sweet-gum tree. 



CHAPTER IV. 

 Buds and Leaves, 



Section I. — Buds. 



51. If in the summer you will observe a branch of hick- 

 ory, oak, or almost any other tree belonging to the exogen- 

 ous family, you will perceive in the axil of the leaf and at 

 the extremities of the branches, little round or oval bodies ; 

 watch them as the season advances, and you will perceive 

 them slightly increasing, and scales forming over them. 

 When autumn robs the tree of its leaves, the protuberances 

 will be found to be arranged along the tree at regular 

 intervals, either alternate, opposite, spiral, or in whorls. 

 These points of situation of the buds are called nodes, 



52. In some cases these are covered with a substance 

 not unlike varnish. The object of these scales and this 

 varnish will be very evident when you are told that in the 

 little bud is wrapped the infant leaf or flower of the coming- 

 spring. Cut the bud of the hickory (I mention this be- 



51. What is the subject of the fourth chapter? What changes occur in a 

 branch of oak or hickory ? When are the buds fonnecl ? 



52. How are buda protected from the cold ? 



