66 AGE OF PLANTS. 
shire, commonly called the yews of Fountain’s 
abbey, are computed to be about 1,290 years old ; 
and the largest of them had, in 1775, a circumfer- 
ence of 264 feet. Two yew trees in Kent, the one 
in the churchyard of Stalesfield, and the other in 
that of Easling, measure each 27 feet in circum- 
ference at the height of four feet from the ground, 
and are believed to be about 1,300 years of age. 
A yew tree, which was growing in 1660 in the 
churchyard of Brabourne in Kent, but all local 
tradition of which is lost, measured at that time 
very nearly 60 feet in circumference at the base, 
and is believed to have been 2,880 years of age. 
There is at present a yew tree growing in Darley 
churchyard, near Matlock, of the girth of 33 
feet. It is the opinion of Decandolle, that of all 
European trees the yew is that which attains the 
greatest age. “I have measured the deposits of 
one of seventy years; (ilhafen has measured one 
of one hundred and fifty years ; and Veillard has 
measured one of two hundred and eighty years. 
These three measurements agree in proving that 
the yew grows a little more than one line an- 
nually in the first one hundred and fifty years, 
and less than a line from one hundred and fifty 
to two hundred and fifty. If for very aged yews 
we take the average of one line annually, it is 
probably an admission beyond the truth ; and 
thus in estimating the number of lines and years 
as equal, we make them younger than they really 
are.” Some cypresses, which were growing in 1776 
in the palace-garden of Grenada, were supposed to 
be then 800 or 900 years old. A species of cypress 
(Cupressus disticha), which grew near Oaxaca in 
Mexico, and which is said to have sheltered the 
whole army of Cortes, measured nearly 118 French 
feet in circumference, or 374 feet in diameter, and 
was computed by Decandolle to have withstood 
the deluge, and been in existence before the crea- 
tion of man. “ But,” says Humboldt, “on ex- 
amining it narrowly, M. Anza observes, that what 
excites the admiration of travellers is not a single 
individual, but that three united trunks form the 
famous Sabino of Santa Maria del Tuli.” The fact 
of the threefold nature of the stem, seems to have 
escaped the notice of some writers; it is of im- 
portance in determining which is really the largest 
organic monument of our planet. There is another 
cypress at Chapultepec in the same region, which 
is said to be 117 feet 10 inches round. If the 
measurement here given be correct, and the tree 
consists only of one stem, we are entitled to re- 
gard this Mexican cypress as the most gigantic 
and ancient tree hitherto discovered on the globe. 
The ceroxylon of the Andes, a2 monocotyledonous 
tree, attains a height of 180 feet, and is supposed 
to live about 900 years. The celebrated dragon- 
tree of Teneriffe, another monocotyledonous plant, 
is alleged by tradition to have been as large and 
as hollow at the discovery of the island in 1402 
as at»present; and, when measured by Hum- 
boldt, it had a circumference of 45 feet near the 
ground, and a diameter of 16 feet. The won- 
AGENT. 
derful size and appearance of this tree excited 
the admiration of Humboldt, who thus describes 
it :-—“ We were told that the trunk of this tree, 
which is mentioned in some very ancient docu- 
ments as marking the boundaries of a field, was 
as gigantic in the fifteenth century as it is at the 
present moment. Its height appeared to us to be 
about fifty or sixty feet ; its circumference near 
the roots is forty-five feet. * * The trunk is 
divided into a great number of branches, which 
rise in the form of a candelabrum, and are ter- 
minated by tufts of leaves, like the yucca which 
adorns the'valley of Mexico. It still bears, every 
year, both leaves and fruit. Its aspect feelingly 
recalls. to mind ‘ that eternal youth of nature’ 
which is an inexhaustible source of motion and 
of life. This giant plant was laid prostrate by 
a tempest in 1822.” It has been satisfactorily 
ascertained, that olive trees will live in favour- 
able situations for 300 years. Greuw, in the 
year 1400, cut his name on two boababs, and 
Petiver did the same thing 149 years afterwards. 
In 1749, Adanson saw these trees, and at that 
period they had increased seven feet in circum- | 
ference since the time of Petiver, being an 
interval of 200 years. These trees are, however, 
sometimes found to acquire a perimeter of 435 
feet ; from this it is inferred that they must live 
many thousand years. One of the most curious 
and beautiful of nature’s productions, is the 
banian or burr tree, the cus Indica of botanists. 
Hach tree forms in itself a grove, composed of 
numerous stems connected together, some of 
which are of the size of a large tree. On the 
island of Nerbuddah, near Baroach, in Hindostan, 
there is still standing a celebrated banian, called 
the Cubbeer Burr. The tradition of the natives 
is, that it is three thousand years old. .It is sup- 
posed by some to be the same tree that was visited 
by Nearchus, one of Alexander the Great’s officers. 
The large trunks of this tree amount in number 
to 350, the smaller ones exceed 3,000, and each of 
these is constantly sending forth branches and 
hanging roots to form other trunks. The cir- 
cumference of this remarkable plant is nearly 
2,000 feet. The long period required to ascertain 
the age of trees, renders our knowledge on this 
subject very imperfect ; and it will probably long 
remain so until records are established by scien- 
tific institutions, to ascertain the ages of such 
trees as are public property. See articles GrowTH || 
and TREES. 3 
AGENT. An organic power in the animal 
body, to perform a natural function ; a medicinal 
power in drugs, to attack and dispel a disease ; 
a chemical power in inert substances, to change 
the properties or composition of other substances ; 
a chemical power in manures, gases, electricity, 
or weather, to effect important modifications on 
soils or crops ; in mechanics, the powers or forces 
employed as the first movers of machinery, such 
as the strength of animals, the elastic power of 
steam, the weight of water, and the force of wind ; 
