ly
occasionally bore fruit. If this be correct, the peach, in spreading
during the last two thousand years over the middle parts of Europe,
must have become much hardier. At the present day different varieties
differ much in hardiness: some French varieties will not succeed in
England; and near Paris, the _Pavie de Bonneuil_ does not ripen its
fruit till very late, even when grown on a wall; "it is, therefore,
only fit for a very hot southern climate."[781]

I will briefly give a few other cases. A variety of _Magnolia
grandiflora_, raised by M. Roy, withstands cold several degrees lower
than that which any other variety can resist. With camellias there is
much difference in hardiness. One particular variety of Noisette rose
withstood the severe frost of 1860 "untouched and hale amidst a
universal destruction of other {309} Noisettes." In New York the "Irish
yew is quite hardy, but the common yew is liable to be cut down." I may
add that there are varieties of the sweet potato (_Convolvulus
batatas_) which are suited for warmer, as well as for colder,
climates.[782]

The plants as yet mentioned have been found capable of resisting an unusual
degree of cold or heat, when fully grown. The following cases refer to
plants whilst young. In a large bed of young Araucarias of the same age,
growing close together and equally exposed, it was observed,[783] after the
unusually severe winter of 1860-61, that, "in the midst of the dying,
numerous individuals remained on which the frost had absolutely made no
kind of impression." Dr. Lindley, after alluding to this and other similar
cases, remarks, "Among the lessons which the late formidable winter has
taught us, is that, even in their power of resisting cold, individuals of
the same species of plants are remarkably different." Near Salisbury, there
was a sharp frost on the night of May 24th, 1836, and all the French beans
(_Phaseolus vulgaris_) in a bed were killed except about one in thirty,
which completely escaped.[784] On the same day of the month, but in the
year 1864, there was a severe frost in Kent, and two rows of
scarlet-runners (_P. multiflorus_) in my garden, containing 390 plants of
the same age and equally exposed, were all blackened and killed except
about a dozen plants. In an adjoining row of "Fulmer's dwarf bean" (_P.
vulgaris_), one single plant escaped. A still more severe frost occurred
four