[January BOTANICAL GAZETTE 40 



cannot use, survival remains with the soundest and best developed. 

 The final picking off in ages 3 to 5 seems slight. In the last age the 

 result of unequal battle with parasites comes out and all fall in turn. 

 It is the rare exception that remains to the last age, one of 100,000 

 seedlings that have lived and died within its present sphere of influ- 

 ence (Gleason). In the last age beech is largely replaced by 

 maple in most localities, so that a pure maple-hemlock stand is 

 found in places. 



Seasonal periodicity is shown, for example, in the synfolium, 

 present only during summer and part of spring and fall. Each fall 

 it joins the preceding synfolia in the dead leaf layer, thus proving 

 how little actual solid was in it. Chromatic periodicity is more 

 accentuated than in Illinois. The synfolium is yellowish green in 

 spring, quickly turning to the darker green retained through the 

 summer. In fall the birches turn yellow and many maples scarlet. 

 Growth periodicity is shown in the alternating periods of relatively 

 slow growth and active elongation (especially of saplings) , according 

 as the inhibition of an older generation persists or is removed. 



Evidences of dying or death are unobtrusive but ever present. 

 Nature seems very wasteful in her development of adult trees. 

 The number of saplings pinned down by debris is remarkable. 

 Many are thus actively destroyed instead of passively dying for 

 lack of light. It is needless death and destruction that should in 

 large measure be eliminated by scientific forestry, thus obviating 

 the waste of space and light taken to develop useless plants at the 

 expense of those later useful. Below the sapling synfolium is a 

 death layer which bears, aside from the trunks present, many dead 

 and dying branches. 



Branches do damage in proportion to their size, the culmination 

 of destruction coming in the fall of an adult tree. Tree or branch 

 fall is primarily caused by basal rotting. Wind, rain, or lightning is 

 usually required to crack the last resistant marginal alburnum of a 

 branch or unbalance the tree (which has a different type of balance 

 from a branch, so that it can break through proportionally. much 

 more wood). The big tree rarely catches on others to remain 

 propped for a while. It usually falls without warning, snatching 

 off branches from its neighbors, and pinning down or lacerating 



