260 



CAUSES OF VARIABILITY. 



Ohai\ XXII. 



even as late as the 5th of June. 16 Such facts as these are well 



fitted to show, on what obscure and slight causes variability 



rests. 



I may here just allude to the appearance of new and valuable varieties 

 of fruit-trees and of wheat in woods and waste places, which at first sight 

 seems a most anomalous circumstance. In France a considerable number 

 of the best pears have been discovered in woods ; and this has occurred 

 so frequently, that Poiteau asserts that " improved varieties of our culti- 

 vated fruits rarely originate with nurserymen. 17 In England, on the 

 other hand, no instance of a good pear having been found wild has been 

 recorded ; and Mr. Eivers informs me that he knows of only one instance 

 with apples, namely, the Bess Poole, which was discovered in a wood in 

 Nottinghamshire. This difference between the two countries may be 

 in part accounted for by the more favourable climate of France, but 

 chiefly from the great number of seedlings which spring up there in the 

 woods. I infer that this is the case from a remark made by a French 

 gardener, 18 who regards it as a national calamity that such a number of 

 pear-trees are periodically cut down for firewood, before they have borne 

 fruit. The new varieties which thus spring up in the woods, though they 

 cannot have received any excess of nutriment, will have been exposed to 

 abruptly changed conditions, but whether this is the cause of their pro- 

 duction is very doubtful. These varieties, however, are probably all 

 descended 19 from old cultivated kinds growing in adjoining orchards — a 

 circumstance which will account for their variability ; and out of a vast 

 number of varying trees there will always be a good chance of the appear- 

 ance of a valuable kind. In North America, where fruit-trees frequently 

 spring up in waste places, the Washington pear was found in a hedge, 

 and the Emperor peach in a wood. 20 



With respect to wheat, some writers have spoken 21 as if it were an ordi- 

 nary event for new varieties to be found in waste places ; the Fenton wheat 

 was certainly discovered growing on a pile of basaltic detritus in a quarry, 

 but in such a situation the plant would probably receive a sufficient amount 



16 M. Cardan, in « Comptes Rendus,' 

 Dec. 1848, quoted in 'Gard. Chronicle,' 

 1849, p. 101. 



17 M. Alexis Jordan mentions four 



18 Duval, 'Hist, du Poirier,' 1849, 



p. 2. 



19 I infer that this is the fact from 

 Van Mons' statement (' Arbres Frui- 

 excellent pears found in woods in tiers,' 1835, torn. i. p. 446) that he finds 

 France, and alludes to others ('Mem. in the woods seedlings resembling all 

 Acad, de Lyon,' torn. ii. 1852, p. 159). the chief cultivated races of both the 

 Poiteau's remark is quoted in * Gar- pear and apple. Van Mons, however, 

 dener's Mag.,' vol. iv., 1828, p. 385. looked at these wild varieties as abo- 

 See 'Gard. Chronicle,' 1862, p. 335, riginal species. 



for another case of a new variety of the 20 Downing, ' Fruit-trees of North 



pear found in a hedge in France. Also America,' p. 422 ; Foley, in ' Transact. 

 for another case, see Loudon's 'Ency- Hort. Soc.,' vol. vi. p. 412. 



clop, of Gardening,' p. 901. Mr. Eivers 

 has given me similar information. 



21 ' Gard. Chronicle,' 1847, p. 244. 



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