HYBRIDISING AND CROSS-BREEDING. 95 



Cultural Variability. Doubtless much is attributed to 

 hybridism, which is really cultural variability; and in drawing 

 attention to some phases of the latter, I cannot do better than 

 quote what Professor M. J. Decaisne * says on this subject : 

 " We cannot possibly doubt but that culture has a great ten- 

 dency to cause, or at least hasten, the variability of plants, and 

 this doubtless from the complexity of the elements which it 

 brings into action. Changes or transformations which plants 

 undergo in our gardens are much more rapid, comparatively 

 speaking, than the variability of plants in the wild state. For 

 example, the Poppy, .the Cornflower, the Larkspur, are always 

 very uniform in habit, and especially in colour, in the wild 

 state ; but in the richer soil of our gardens they are modified 

 or changed in. the most remarkable manner. Poppy-flowers 

 pass from scarlet to white, or nearly black, by the extension of 

 the basal spot on each petal : sometimes they are shaded 

 with two or more colours, or the crimped edges of the petals 

 become elegantly fringed, while at other times they become 

 perfectly double. Cornflowers and Larkspurs, the flowers of 

 which are so uniformly blue in the wild state, nearly always 

 change their colours, and that shortly after they are introduced 

 to cultivation, and become white or rose-coloured; or rose blends 

 with blue, and causes the bright metallic shades of bronzy 

 purple so common to Larkspurs or Delphiniums : indeed it is 

 very rare that they preserve their primitive colour. We cannot 

 attribute these variations to crossing with other species, since 

 the flowers are fecundated by their own pollen some time 

 before the expansion of the petals ; and besides, these variations 

 eventually become hereditary, like the specific characters. In- 

 herence of forms is then not the exclusive right of species, since 

 varieties or races of known origin also possess it in an equal 

 or even superior degree, so that permanence of character 

 that is, habit, form, colour, &c. is not an absolute criterion 

 by which to decide that any particular form allied to some 

 other, discovered in a wild state, and recognised as hereditary, 

 is on that account a different species." 



It has frequently been pointed out that in a state of nature 

 plant-life is as a rule in a condition of repose, the heredi- 

 tary firmness of character being sufficient to counterbalance 

 natural disturbing influences; hence the species reproduces 

 itself from seed, and remains in its pure or characteristic 

 state. This balance is so nicely adjusted, however, that if we 

 vary the surrounding conditions of the plant by bringing it into 



* See Annales des Sciences Naturelles (1864), 4 serie, vol. xx. p. 188, 

 or Journal of the Royal Horticultural Society (new series), vol. i. p. 39. 



