ON THE YOUNG BARK. 35 



It is proper also to remark here, that with every increase 

 in the number of leaves spread abroad in the atmosphere, 

 by a young tree or branch, there must be necessarily an in- 

 crease in the rapidity of its growth, because it has a greater 

 amount of leaf-surface at work in the air. Its chances of 

 life, and of arriving at a state of maturity, become greater as 

 its leaves increase in number. But this law must be under- 

 stood with considerable modifications. 



It will be seen by reference to the Table and the Plate, 

 that the growth of the branch was greatly retarded from 

 1855 to 1856. The primary axis that season grew only four 

 lines, and the ten secondary axes were also equally kept 

 back, so that very little wood was formed that year; alto- 

 gether it amounted to only three inches and seven lines. 

 Yet there were thirty leaves at work that season, being four 

 more than was put forth the previous year, when a much 

 greater amount of work was done, twenty-six leaves forming 

 not less than twenty-seven inches and six lines of new shoot. 

 It is clear from this, that growth is proportionate, not so 

 much to the amount of leaf-surface spread forth in the atmo- 

 sphere, as to the vital activity of the leaves themselves. 



Again, by consulting the Table, it will be seen that al- 

 though twenty-eight leaves were employed in constructing 

 the primary axis, yet only ten produced buds which ulti- 

 mately became branches; also, that these ten branches, 

 although constructed by one hundred and twenty-seven 

 leaves, developed only seventeen shoots, as is evident by add- 

 ing together the sum of the figures at the bottom of the 

 columns marked S, under "Secondary Axis ; ;; it follows, that 

 of these one hundred and twenty-seven leaves only seven- 

 teen produced vitally active buds. Therefore, the total 

 number of abortive or rudimentary buds in the entire branch 

 must be 155 (17+10) = 128. 



The number of shoots annually put forth, were, in 

 1853,1; 1854,3; 1855,13; 1856,0; 1857,10; 1858,0. 



The increase in the growth of the entire branch was, in 

 1853,4; 1854,8-7; 1855,27-6; 1856,3-7; 1857,18-8; 1858,19-9: 

 that is to say, in 1853, the branch grew four inches, in 1854, 



