•274 
LONGEVITY OF PLANTS. 
to rye. Rust is chiefly confined to the grasses ; both are of 
the fungi family. 
6th. Diseases resulting from age. Plants differ from animals 
in one important circumstance ; the latter develope their organs 
at once, these organs in progress of time become indurated, and 
obstructed until they at length decay from old age. Plants, on 
the contrary, renew themselves every year ; that is, they form 
new vessels to convey the juices, new leaves to elaborate them 
and new buds to produce flowers and fruits. Plants do not 
then like animals, seem destined to die with old age ; or there 
does not seem to be in perennial plants any prescribed term of 
existence. The producing of fruit appears to exhaust the vital 
energy of the plant, in annuals in one year, in biennials in two, 
in perennials, in a longer or shorter period according to their 
natural constitution, and the quantity of fruit which they pro- 
duce. Apple trees which bear heavy loads of fruit, are very 
short lived in comparison with the oak, which perfects from 
each flower, but one of six seeds, and this fruit is but a small 
acorn. 
There are some trees now known to exist, which are supposed 
to be of great age ; in the Island of Teneriffe is the Dracaena 
draco , which according to many circumstances may seem to 
have some thousand years of age. In England at Bolenheim 
Park, it is said, may be seen trunks of trees which shaded the 
bower, of fair Rosamond, and which it is supposed are not less 
than a thousand years old. 
At Hartford in Connecticut is the charter oak, which was an 
old hollow tree in the days of James II. 143 years ago. In 
the hollow of this tree was concealed the charter of the state 
when the King of England, through his agents attempted to 
deprive the colonists of that guarantee of their civil rights. 
This oak must even at that period have been an aged tree. 
Cultivation of Plants. 
77 'ees. We find the trees of tropical regions to be much 
more varied in their characters than in more northern regions ; 
the same fact may be observed in ascending mountains, whose 
bases often present oak, walnut, birch, chesnut, &c, while their 
summits afford only pines and firs. 
The surface of the earth seems naturally divided into forests 
and meadows ; the most extensive kind of the latter division, is 
exhibited in the steppes or prairies of the western regions of the 
United States, extending to an immense distance with no other 
vegetation than tall grass which rises to the height of six or 
eight feet. 
Diseases resulting' from old age — Aged trees. — Cultivation of plants — 
Tices — Their comparative variety in tropical regions — Forests and mea- 
dows exhibited in steppes and prairies. — 
