THE NATURAL HISTORY OF A BEECH TWIG. 369 
These make up by their immense numbers and their persistent 
nature for their want of surface, and thus contribute to the 
growth of the branches of these trees, as completely as those 
which possess a true lamina or blade. 
Again, the increase of leaf surface each year, as ascertained 
by calculations made on the original twig, was as follows : — 
1851, 5; 1852, 10; 1853, 14; 1854, 15; 1855, 23; 1856, 
28; 1857, 29; 1858, 36; 1859, 38; 1860, 37; 1861, 36; 
1862, 40; 1863, 44. That is to say, in 1851 the twig put 
forth five leaves ; in 1852, ten leaves, &c., &c. 
It is worthy of remark here, that with every increase in the 
number of its absorbent surfaces or leaves, a young tree or 
branch must necessarily grow more rapidly. At any rate this 
law holds good up to the time when the tree begins to arrive at 
a maximum in its height and in the spread of its boughs ; for 
till then the amount of leaf surface put forth in the atmosphere 
increases continually. When this period approaches, however, 
the vitality of the leaves put forth on the shoots at the extremi- 
ties becomes enfeebled, and the shoots themselves become every 
year more and more circumscribed in their growth. The 
annual crop of leaves is now pretty much the same year after 
year. But the lofty tree, though it stands for hundreds and 
even thousands of years, has an appointed limit to its life, like 
the lowly flower that grows beneath its shade. Sooner or later 
it will begin to die at its extremities and decay in its interior, 
until at length the stem itself is merely a hollow living shell of 
wood, constituting the only bond of connection remaining 
between the roots and the branches which are still covered with 
verdure. As, however, branch after branch dies, the annual 
amount of its leafage necessarily diminishes. It is, however, 
extremely difficult to point out the several stages of stagnating 
and expiring growth, or to prove that a tree will ever die. In 
most cases death is brought about by violent interruptions to 
the natural life-processes. After having braved the storms of a 
thousand years, the tree is at last blown down and uprooted. 
Now busy, active, ever-industrious nature covers its fallen 
mouldering trunk with a shroud of moss and lichen, and there 
it lies in that forest grave-yard until it is again resolved in its 
original elements of earth and air. 
The twig represented in the plate shows beautifully this 
gradual arrest of growth at its extremities, and also the dimi- 
nution of annual produce in the foliage ; thus illustrating 
clearly that law which governs the whole tree as it approaches the 
close of its allotted period of life. Let us confine our observa- 
tions to the primary axis of our twig, which, with its little side- 
shoots, represents the massive stem and branches of the tree 
from which it was cut, on a smaller scale of architecture, being 
