390 Objerwations on the. Growth of Trees 
. «E H E. idea has univerfally obtained, that Trees grow from: 
the root upwards. But perhaps it may appear probable, from ` 
the ‘following confiderations,. that Trees, em the firft year, : 
grow from the top downwards. 
"The growth of annual plants feeme to Ls the mere expand- 
ing ôf the parts contained in the feed, or bulb, which is amore - 
perfec and full grown feed, differing but little from what is 
conari called feed. Of this, the bulb of a tulip is the beft 
example, ds the parts are vilible without the help of glaffes. 
Upon removing the feveral coats of the bulb, each of which 
are the fapport of a leaf, in the center of it, a large flower, 
near half an inch in length, will be found, and, in thicknefs, 
as large as a rye-ftraw ; in which the petals, ftile, filaments 
and buttons are fully KI Bd, and perfect in every refpect but 
fize'and colour. ‘The lower leaf of the plant, which, within 
the bulb, covers all the reft, fwells and expands firft : then the 
next above {wells and expands ; and fo on, until the whole are ' 
expanded : after which, the ftalk rifes, the flower fwells and. 
opens, and its beautiful colours are feparated and exhibited to _ 
the eye. In this growth the bulb is entirely wafted, except. 
only the fine fkin that covered each fquamina, which remains | 
much thinner than white paper. In the center of the bulb, 
below the leaves and adhering to the ftalk, may be feen a very 
{mall bulb, much Jefs than the feeds of the plant, This-bulb. 
is, however, increafed with the gr- wth of the leaves, until it 
becomes of the fize 'of the parent bulb : and when the ftalk, - 
the leaves and fibrous roots decay and dry up, this new bulb 
remains, in the place of the old Sed, capable of a like growth - 
the next year. ! 
p E. WW ou 
E xe c ` fa " " 
