

314 



LAWS OF VARIATION. 



Chap. XXI V. 



The laurel, bay, laurestinus, &c, and the Jerusalem artichoke 

 which are propagated by cuttings or tubers, are probably now 

 as tender in England as when first introduced ; and this appears 

 to be the case with the potato, which until recently was seldom 

 multiplied by seed. With plants propagated by seed, and with 

 animals, there will be little or no acclimatisation unless the 

 hardier individuals are either intentionally or unconsciously 

 preserved. The kidney-bean has often been advanced as an 

 instance of a plant which has not become hardier since its first 

 introduction into Britain. 



authority 

 produced 



80 



that 



We hear, however, on excellent 

 very fine seed, imported from abroad 



which blossomed 



profusely, but 



ly all but abortive, whilst plants grown alongside from 

 English seed podded abundantly ;" and this apparently shows 



some degree of acclimatisation in 



have 



English plants. We 



that seedlings of the kidney-bean occasionally 



appear with a marked power of resisting frost : but 



far as I can hear, has 



separated such hardy seedling 



prevent accidental crossing, and then gathered their seed 



and repeated the 



pr 



year after year. It may, however. 



be objected with truth that natural selection ought to have 

 had a decided effect on the hardiness of our kidney-beans ; for 

 the tenderest individuals must have been killed during every 



severe spr 



bo 



and the hardier preserved 



But 



should be 



m mind that the result of 



eased hardiness would 



simply be that gardeners, who are always anxious for as early a 

 crop as possible, would sow their seed a few days earlier than 

 formerly. Now, as the period of sowing depends much on the 

 soil and elevation of each district, and varies with the season ; 

 and as new varieties have often been imported from abroad, can 

 we feel sure that our kidney-beans are not somewhat hardier? 

 I have not been able, by searching old horticultural works, to 



this question satisfactorily 



On the whole the facts now given show that, though habit 



does something towards acclimatisat 



appear 



yet that the sponta 



of constitutionally different individuals 



far more effective agent. As no single instance has been 



ecorded, either with animals 



- 



plants, of hardier individual 



80 



Messrs. Hardy and Son, in < Gard. Chronicle,' 1856, p. 589. 



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