~ downward, after the fir Year> 49r 
- "The firft year’s growth of a tree, like that of plants, is the 
mere expanfion of the parts contained within the feed, fo far 
as thofe parts are fitted for growth ; and being expanded, the 
wood formed has no further growth, in any dire&ion, but res 
mains of the fame fize until it decays. Each leaf which grows 
on the firft year’s fhoot, as well as thofe of fucceeding years, 
has annexed. to it, immediately above its ftem, an embryo bud, 
which is nourifhed and fitted to grow the following year, and 
to become a branch of the future tree. The leaf having per- 
formed its maternal duty,- falls to the ground, and manures the 
tree from whence it fell. 
The wood of thefe faplings of a year, is uniformly of one 
texture ; but the wood of the next year is feparated from i it bya 
circular line, which remains as long as the wood lafts. Every 
fucceeding year is diftinguifhed in the fame manner ; fo that by 
cutting the tree on one fide, from. the circumference to. the cen- 
ter, and counting thofe circles, you may afcertain its age. 
And one of the main queftions, arifing in the confideration of 
this fubje&t, is, how are thefe annual additional circles of wood 
fred A Are they formed by the. filling and. expanding of 
which, too fmall for the obíervation of our fenfes, lie 
between the i and the tree? or are they new fibres fhooting 
either from below or from above ?. It appears, by examining 
the wounds of trees, that. the wood being once feparated never 
heals up and grows together. —The new wood grows over, and 
covers the wound ; bat the feparated veffels never unite again : 
th ; er efore, i the edge of a knife be pafied eranty erfely thro’ the 
bark half. round alapling, and thofe fappofed extreme fine veficls 
were cut off, that fide of the tree ought to ceafe growing, and 
ihe. buds above it perifh. But the fact is other wife : for, cover: 
the 
