ACCLIMATATION OF PLANTS. 
better. From every observation, it appears, that 
those plants which have the least sap in winter, 
or whose sap is of a resinous or oily nature, suffer 
least from cold. It would be foreign to our pur- 
pose to enter into a discussion of the cause of 
this, or of the theories that have been built upon 
it; suffice it to say, that it has been supposed 
that the principal cause of the destruction of 
tender plants in winter, is owing to the vessels 
being burst by the freezing of the sap. In choos- 
ing plants, therefore, for our experiments, we 
should attend to their organization: annuals 
bear exposure better than perennials; and those 
abounding in sap, having a spongy, porous wood 
and much pith, succeed with difficulty. It seems 
advantageous that those plants to be tried should 
be deprived of moisture as much as possible. 
Mr. Strut found that, when planted above drains, 
several reputed greenhouse species have flour- 
ished most luxuriantly. Plants do not suffer 
from frost in dry situations, nearly so much as 
they do in moist, or when an excess of rain is 
followed by a severe frost. The reason is evi- 
dent,—in moist situations, part only of the mois- 
ture is evaporated during the day, the rest re- 
maining to be converted into ice by the cold of 
the ensuing night. This icy covering increases 
the cold, till the vital principle, and resistance 
given by the formation of the bark to the en- 
trance of the cold, are overcome; the sap is fro- 
zen, and the vessels burst by the expansive force 
of freezing.” 
Any farmer of ordinary intelligence and skill 
may easily turn the doctrines of acclimatation to 
considerable practical account. He will as nearly 
as possible calculate the comparative warmth and 
coldness of the different soils and situations upon 
his farm; and if these should exhibit very sen- 
sible differences and gradations, he will not in 
every instance subject the whole to indiscrimi- 
nate cropping and rotation, but will occasionally, 
or as often as comports with higher considera- 
tions, assign the warmest soils and situations to 
the most tender varieties of plant, and the soils 
and situations of quickest power to such varieties 
| as are tardiest in ripening. He will regard the 
thorough draining of light land as equal to a re- 
moval some lines nearer the equator, and as pro- 
bably capacitating his field to produce a species 
or a variety seldom hitherto grown so far to the 
north. He may occasionally harden a new and 
favourite but somewhat tender variety of a plant 
by growing it, for a series of years, under con- 
ditions at first fostering, and afterwards less and 
less genial. He may possibly introduce a half 
tender garden-plant to the fields, or a plant of a 
warmer zone to a colder one, by cultivating his 
earliest specimens with care, and afterwards com- 
bining from year to year a lowering of the con- 
ditions of culture with a strict selection of seeds 
from only the healthiest and strongest plants. He 
may work out rapidly maturing varieties of grain, 
ao as may be suitable for the most backward 
ACETABULUM. 
33 
soils and situations, by sowing an existing early 
variety, selecting his seed-corn for next season 
only from a few plants of it which ripen before the 
great bulk of the crop, and repeating this process 
for a brief series of years. He may, in one word, 
conduct one set of acclimating experiments on a 
small plot expressly allotted to them, and another 
set co-ordinately with his routine business of cul- 
ture and cropping; and may, as the result, effect 
upon several of the most useful species or varie- 
ties such modifications as will both increase the 
profits of his farm and render him a benefactor 
to his profession and to society at large. A few 
experiments, so far as they do not waste his time 
or substitute any speculative practice for sound 
and well-tested husbandry, can at all events do 
no harm, and will at least produce the incidental 
good of increasing his acquaintance with the 
vitality and the functions of plants. 
A gardener, of course, commands a far wider 
scope for acclimating than any mere farmer. 
Plants which he wishes to acclimate, in the broad 
sense of that word, should be placed in the open |: 
air at the beginning of summer, turned out of 
their pots into poor and very dry soil, and shel- 
tered from the east and north winds; they ought 
to be removed from the hothouse to the green- 
house, from the greenhouse to the open frame, 
and from the open frame to the open border,— 
covered up during the whole of the first winter, 
and covered wholly, partially, or not at all dur- 
ing the second, according to the comparative 
mildness or severity of the weather. Plants in 
a warm climate perspire more than in a cold one, 
and therefore require a larger supply of mois- 
ture; so that while plants remain in a hothouse, | 
they should be abundantly supplied with water, 
—when they become transplanted to the frame 
and to the border, they should have a drier soil. 
— Quarterly Journal of Agriculture.— Loudon’s 
Gardener's Magazine-—Transactions of the London 
Horticultural Society—Keith’s Botanical Lexicon. 
—Loudon’s Encyclopedia of Agriculture. —Dr. 
Macculloch on the Naturalization of Plants, in the 
Quarterly Journal of Science, vols. xxi. and xxvi. 
ACCOUNTS. See Farm Accounts. 
ACER—popularly Mariz. A numerous and 
important genus of forest-trees and tall shrubs, 
represented by the well-known false-plane or 
sycamore. They are, for the most part, distin- 
guished by either the beauty of their appearance 
or the very valuable nature of their timber; and 
they comprise about thirty species, and consti- 
tute the type of the botanical tribe or order called 
Acerinese. See Mapiu. The tribe Acerinez in- 
cludes also the genus Negundium or box-alder, 
and is related to two orders which have for their 
types the lime-tree and the Barbadoes cherry,— 
Tilia and Malpighia; and its trees grow only in 
the northern hemisphere, chiefly within the tem- 
perate zone, and all, more or less, yield a sac- 
charine sap, from which sugar can be made. 
ACETAB/ULUM. The herb penny-grass. Also 
C 
