458 
ACCLIMATATION OF PLANTS. 
doubt that they have to endure greater hard- 
ships on the mountains of Mexico, than they 
do in our ordinary winters ; but this has 
nothing to do -with the question of acclima- 
tation. We have all through maintained that 
it is impossible to alter in any plant its powers 
of endurance. The only way properly to 
ascertain a plant's powers of endurance is to 
gradually change its temperature, until it is 
placed in the open ground ; and to select 
several positions, even those of different cir- 
cumstances, as north, south, east, and west 
aspects, with a registering thermometer at 
each place. The conditions most favourable to 
a plant are those which involve the least 
change, and that change the most gradual. 
It will often be found, that when there is no 
protection, a plant under a south wall, or a 
south-west, will perish, while one in a northern 
or a north-eastern exposure will survive ; 
the one never being so greatly excited as the 
other, is consequently never subject to such 
great changes, and hence its endurance. The 
plant placed in the coldest aspect, having no 
sun to act upon its frozen juices, gradually 
thaws ; while that which is subject to the 
immediate operation of a hot sun, which fre- 
quently succeeds a frost, is often very suddenly 
acted upon. But there are circumstances 
under which plants may succeed better than 
they generally do, and among them there are 
certain conditions that can be supplied : for 
instance, gravelly bottom, good drainage, 
poor compost, shelter from the north-east 
winds, are all favourable to a plant that is 
susceptible of injury from cold ; not that 
these circumstances alter the plant, but they 
change the nature of what it has to bear. 
The gravelly bottom is always warmer, the 
good drainage always tends to the same end, 
the poor soil keeps the plant from growing 
too rapidly, and the shelter is of the greatest 
-consequence ; but if, notwithstanding all these 
circumstances, the winter is severe enough to 
overcome them, the half hardy plant that 
would go through some winters will perish. 
It will bear no more hardship, after all that 
can be done for it, than it would have borne 
without so much coaxing, because all that has 
been done only changed the hardships it had 
to go through, and not the constitution of 
the plant itself. 
But let us now consider how far, according 
to Mr. Johnson's notions, the offspring of 
tropical plants raised from seed may be 
rendered much more hardy than their parents. 
Now we deny that a seedling can be rendered 
more hardy than the parents ; although we do 
admit that seedlings may be more hardy than 
their parents. Our opinions are founded on this 
one fact : — Among plants known to be tender, 
the dahlia, potato, and some other subjects, 
something has been done in the way of seed- 
lings, and in a batch of many, some will be 
found affected by the frost more than others. 
Among brocoli, cauliflowers, and some other 
subjects, it is known that the seedlings will in 
some cases differ from the parent, — some will 
endure the winter better, some come earlier, 
some stand better, in short, it is not at all un- 
common to see a visible change in many of the 
plants. The new varieties of peas, cabbages, 
cauliflowers, brocoli, turnips, melons, cucum- 
bers, and all kinds of fruit, have been obtained 
from seed, and the constant variations to be 
found in seedlings from a known parent, show 
us distinctly that it is fair to hope that in a 
limited degree there may be a progeny some- 
what more hardy than the parent. 
"We were once going through an immense 
piece of brocoli, after the extreme hard 
winter so often called Murphy's, when, on or 
about the 11th January, there was the hardest 
frost known in England. It was as difficult 
to find a bit of vegetable alive as if every- 
thing had been burned up. On this occasion 
there were (among a wreck of thousands of 
plants, which were rotten and perished and 
putrid,) two or three plants as strong and 
healthy as if there had been no frost ; we 
remarked at the time they were valuable 
exceptions to the desolation around, and that 
their seed would pay more than the whole 
crop would have done. All that we could get 
out of the gardener was, that the family must 
have those three heads, and he could not save 
them ; and so it was, the family or some part 
of it had noticed them and ordered them to be 
cut for dinner. The gardener would have lost an 
excellent sort, or rather three excellent sorts, 
for one was completely sprouting, one a rather 
dark, and the other a white head. Here was 
evidently hardier offspring than the rest of 
the seedlings appeared to be, and we can 
hardly doubt that in every description of plant 
it is possible to obtain plants hardier than the 
parent, though not very commonly so without 
hybridizing, as it is called, that is, impreg- 
nating or fertilizing a hardy kind of plant with 
one of the tender, and so producing hardy 
plants with the principal characters of the 
tender one. At all events, there is no deny- 
ing that if seed be saved as carefully as 
possible, and seedlings raised from it, there 
will be found differences in the seedlings in 
foliage, in habit, in hardiness, and in other 
properties that render the plants more valu- 
able ; while, on the other hand, there will be 
discovered many much Avorse than the original. 
So long therefore as variation is to be found 
in seedlings, as compared with the parent 
plants, so long there must be allowed a 
possibility for some to be more hardy than 
their parents ; but we maintain that practically 
