The Sun.
London, England, 1863-07-16 00:00:00

THE ARMY.

The 20th ltegiment will embark at Portsmouth
for foreign service on the 22d and 25th inst.
The 64th Regiment will arrive in Portsmouth
garrison for permanent duty from Aldershott on the
Ist proximo.
Orders have been received at the head-quarters
of the Royal Engineer establishment from the
Horse Guards, directing a number of the most ex-
perienced telegraphists, who have completed their
course of instruction at the School of Telegraphy,
Brompton Barracks, to be selected from the compa-
nies at headquarters, to be despatched to Turkey to
assist in laying down a telegraph line through
that country and Persia to India. The non-corn-
commissioned officers and men selected for this
duty will be absent from Ergland for several
years, and in consequence of the arduous nature
of the undertaking on which they will be engaged,
they will receive a high rate of pay. It is ex-
pected that the expedition to be despatched ii:om
Chatham will be occupied for about five years in the
undertaking.

PEAR-TREES.—On the subject of fruit trees,
botanists are divided into two parties ; one, which
may be called the Linna3an party, admits the variability of
species; the other denies it. Hence, while the former con-
tents itself with few species, each comprising numerous
varieties, the other counts a large number of species, which
it declares to have existed ab initio, and not to have de-
scended by slow degrees from any of the other species. M.
Decaisne, in a paper communicated last week to the Aca-
demy of Sciences, endeavours to supply the positive proof of
the variability of species, the want of which has always been
triumphantly pointed out by the latter party. In the case
of the pear-tree for instance, if this proof be wanting, the
number of species will amount to upwards of 500,
all of which according to M. Jordan, of Lyons,
must be assumed to date from the ante-diluvian
period. The following are M. Decaisne's experiments to
show the fallacy of these views. In 1853 be sewed four
n
different varieties, viz,, the old English pear;
thellosome
pear, which is shaped like a calabash and of
and a cinnamon
colour ; the Belle Alliance, which is roundish
yellow and red ; and, lastly, the Sauger pear, which is
almost a wild species. Of the latter,
four trees grown
from the seeds have borne fruit, and each a different
another,
streaked
variety, via., one of an oval shape, green;quitee;
a third still
green and red, and nearly as round as
shape appleofa
pear, much
an
flatter, and a fourth having the usual
quite
yellow. The Belle
larger than the others,
and
varieties, none resembling
Alliance yielded nine different var
is twice as large as the
the original one; of these one is.
The Bose variety
latter, and another is bergamot
ones of which was so like
produced three different. typos,
S u erpear as to be easily
one of those obtained from the
.a g .
it. Lastly, the English pear yielded six differ-
mistaken for
varieties, one of which bore a marked resemblance to the
eSnatint-Germain kind. The difference was not perceptible in
the fruit alone, but also in the leaf, the general appearance
of the tree, and the period of ripening. Every one of the
trees looks different ; some are thorny, others not ; in some
the trunk has a small diameter, in others it is thick and
knotty. M. Decaisne enumerates various other differences
in the flowers, the sap, g,
—c. lie does not believe that graft-
ing modifies the nature of the pear, nor does he admit that
the pips of a good pear 'will produce the wild plant, as is
generally supposed. From all this M. Decaisne concludes
that the theory of invariable species is unfounded.