32 



trees as the Big Cypress Tree of Tule found in the state of Oaxaca, 

 Mexico, or the Sequoia of California. 



It is not always easy to tell the age of a tree or that of an even- 

 aged stand of trees. Planting records are often very valuable in 

 determining their exact age. The best means of finding out the 

 exact age of a tree is to ask the owner who kept a record when the 

 tree was planted. This method may be used for some ornamental 

 trees and for forest stands which were artificially established. De- 

 tailed records should be kept of all forest stands whether established 

 artificially or naturally. The determination of the age of trees in 

 the original forest or in an unregulated forest is a more difficult 

 task. The age of a young tree like that of a child is more readily 

 determined than that of an old tree. The best test for telling the 

 age of a tree, if planting records are wanting, is to count the an- 

 nual rings on a cross-section of the stem near to the ground and 

 adding to this number, as many years as it took the tree to grow to 

 that height. (Plate I, two lower series of drawings, and Plate XI, 

 1, 3). Each ring usually represents the growth of one year. A sec- 

 ond test will apply to such species as White Pine, which develop 

 their lateral branches in distinct and rather regular whorls. (Plate 

 I, upper right figure, and Fig. 19). Each whorl normally represents 

 a year's growth. If the branches have fallen off one can often find 

 the scars of the branches on the stem. (See Frontispiece and Figs. 

 25 and 26). The age of young trees or small branches can also be 

 determined by counting the rings of terminal bud-scale scars (Plate 

 I, upper left figure). The portion of the branchlet from the end 

 down to the first ring of bud-scale scars represents the last season's 

 growth while that between the first and second rings represents the 

 next to the last season's growth and so on. To tell the age of trees 

 may sometimes be difficult but it is usually fascinating. After you 

 have been successful in determining the age of a few trees, you may 

 find yourself questioning the age of others as you walk or drive 

 by them. A careful study of their growth will often indicate the 

 successes and failures which they met during their development, 

 since a relatively narrow ring often indicates a struggle, while a 

 wide ring often indicates favorable growth conditions. 



THE ^ FORM AND STRUCTURE OF TREES. 



1. Form : 



By form is meant the general appearance of a tree. One can 

 study the form of deciduous or broad-leaved trees best in winter 

 when they are devoid of their foliage. After one is familiar with 

 the general form of different trees it is possible to distinguish the 

 different species even at a great distance. The form, together with 



