PRINCIPLES OF AMEEIOAN FOEESTRT. 



CHAPTER I. 

 THE TREE. 



I 



A TREE is a woody plant with a single stem more or less 

 branched and taking on what is commonly known as the 

 tree form. 



The most evident parts of a tree are roots, stem or trunk, 

 branches, buds, leaves, flowers, fruit, and seed. 



The Stem, Branches, and Roots are made up of inner 

 bark, outer bark, sapwood, and heartwood. The outer bark, 

 sapwood, and heartwood are made up of concentric circles 

 termed annual rings. During each period of growth two 

 new rings are formed — one on the outside of the sapwood 

 and another on the inside of the outer bark, and as we sel- 

 dom have more than one season of growth each year but 

 one ring is formed on the wood in a year; so that by 

 counting the rings of wood in the stem we can determine 

 very closely the age of trees. In very rare cases we have 

 two periods of growth and two rings of wood in one year, as 

 in 1894, when the drought of midsummer ripened up the 

 wood of the trees by the first of August and the rains of 

 autumn started a new growth and caused some trees and 

 shrubs to flower in October, but such occurrences are very 

 uncommon and the extra rings formed are readily detected 



