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 m 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 

 understood 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 ; 

 altogether 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 atmosphere, 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 

 adding 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 

 seventeen 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; 185T, 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, 



