The orange was very
tender when first introduced into Italy, and continued so as long as it
was propagated by grafts, but when trees were raised from seed many of
these were found to be hardier, and the orange is now perfectly
acclimatised in Italy. Sweet-peas (Lathyrus odoratus) imported from
England to the Calcutta Botanic Gardens produced few blossoms and no
seed; those from France flowered a little better, but still produced no
seed, but plants raised from seed brought from Darjeeling in the
Himalayas, but originally derived from England, flower and seed
profusely in Calcutta.[36]
An observation by Mr. Darwin himself is perhaps even more instructive.
He says: "On 24th May 1864 there was a severe frost in Kent, and two
rows of scarlet runners (Phaseolus 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 (Phaseolus vulgaris) one single plant escaped. A still more
severe frost occurred four days afterwards, and of the dozen plants
which had previously escaped only three survived; these were not taller
or more vigorous than the other young plants, but they escaped
completely, with not even the tips of their leaves browned.
Pages:
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177