35 CLAYBERG— UPLAND SOCIETIES 1920] 



seedlings germinate to fill the gaps, and elongation results in the 

 formation of a new sapling stand (age 2) as the trees above reach 

 age 4. The sapling axis is long and straight, forks and side branches 

 equaling the stem are rare, and the foliate part of the tree, although 

 polygonal in cross-section, approaches a right cylinder. The 

 lowest branches are dead twigs, the later ones are horizontal or 

 angle up. 



A fine close sapling stand is the culmination in percentage of 

 volume occupied. As the size of a stand increases, the distances 

 between its trees increase also, and it is believed that a law will here 

 be found to control relation of diameter and spacing of trees. The 

 sapling age shows maximum increase in size for given decrease in 

 number per unit area, hence competition between trees of equal 

 age is keenest here. 



With removal of another generation the saplings elongate, but 

 intensity of vertical growth decreases, for the relatively open 

 spacing permits lateral growth and reapproach to the typical 

 broad form shown by isolated trees in field and pasture. In passing 

 from the second to the third age a transition in branch form is seen, 

 from the filiform type of evanescent branch to the massive type of 

 permanent branch characteristic of the adult. These originate far 

 above the sapling tops and hence are developed later. Comparison 

 of the young adult and sapling stages with regard to ratio of height 

 to breadth suggests partial etiolation in the latter. All saplings 

 with forked axes are eliminated, since no adults are seen with forks 

 at sapling level. Naturally a biaxial shoot is at a disadvantage 

 under active competition with those supporting but one. 



With further thinning of population the adult stage (age 4) is 

 reached. This is the true ecological climax. The maximum foliage 

 display and culmination of vitality are seen here. A typical tree was 

 studied, felled, and measured. There was no sign of lost branches 

 or decay, all branches bearing a rich display of leaves in normal 

 position. The trunk was clean, straight, and subcylindric, with 

 the lowest branch 25 .3 m. from the ground. The diameter basally 

 was 53 cm. and the tree was 32.5 m. tall. The crown was oval, 

 with i 2 major branches. The duramen showed a central cavity 

 8 cm. wide at the base, with its cone point ending about 2 m. above 



