Chap. XXIIL CONDITIONS OF LIFE. 267 



in certain tropical countries. 23 The Rhododendron cih'atum produced 

 at Kew flowers so much larger and paler-coloured than those which 

 it bears on its native Himalayan mountain, that Dr. Hooker 2i would 

 hardly have recognised the species by the flowers alone. Many 

 similar facts with respect to the colour and size of flowers could 

 be given. 



The experiments oi Yilmorin and Buckman on carrots and 

 parsnips prove that abundant nutriment produces a definite and 

 inheritable effect on the roots, with scarcely any change in other 

 parts of the plant. Alum directly influences the colour of the 

 flowers of the Hydrangea. 25 Dryness seems generally to favour the 

 hairiness or villosity of plants. Gartner found that hybrid 

 Yerbascums became extremely woolly when grown in pots. Mr. 

 Masters, on the other hand, states that the Opwntia leucotricha " is 

 " well clothed with beautiful white hairs when grown in a damp 

 " heat, but in a dry heat exhibits none of this peculiarity." 26 Slight 

 variations of many kinds, not worth specifying in detail, are retained 

 only as long as plants are grown in certain soils,, of which Sageret 27 

 gives some instances from his own experience. Odart, who insists 

 strongly on the permanence of the varieties of the grape, admits- 8 

 that some varieties, when grown under a different climate or treated 

 differently, vary in a slight degree, as in the tint of the fruit and in 

 the period of ripening. Some authors have denied that grafting 

 causes even the slightest difference in the scion; but there is 

 sufficient evidence that the fruit is sometimes slightly affected in 

 size and flavour, the leaves in duration, and the flowers in appear- 

 ance. 29 



There can be no doubt, from the facts given in the first 

 chapter, that European dogs deteriorate in India, not only in 

 their instincts but in structure ; but the changes which they undergo 

 are of such a nature, that they may be partly due to reversion to a 

 primitive form, as in the case of feral animals. In parts of India the 

 turkey becomes reduced in size, " with the pendulous appendage over 

 the beak enormously developed." 30 We have seen how soon the wild 

 duck, when domesticated, loses its true character, from the effects of 

 abundant or changed food, or from taking little exercise. From the 

 direct action of a humid climate and poor pasture the horse rapidly 

 decreases in size in the Falkland Islands. From information which 



23 Godron, 'De l'Espece,' torn. ii. 27 ' Pom. Phys.,' p. 136. 



p. 52. 28 'Ampelographie,' 1849, p. 19. 



24 ' Journal of Horticultural Soc.,' 29 Gartner, ' Bastarderz.,' s. 606, 

 rol. vii., 1852, p. 117. has collected nearly all recorded facts. 



25 'Journal of Hort. Soc.,' vol. i. p. Andrew Knight (in 'Transact. Hort. 

 160, Soc.,' vol. ii. p. 160) goes so far as to 



26 See Lecoq, on the Villosity of maintain that few varieties are abso- 

 Plants, ' Geograph. Bot.,' torn. iii. pp. lutely permanent in character when 

 287, 291 ; Gartner, 'Bastarderz.,' s. propagated by buds or grafts. 



261 ; Mr. Masters, on the Opuntia, 30 Mr. Blyth, in 'Annals and Mag 



in ' Gard. Chronicle,' 1846, p. 444. of Nat. Hist.,' vol. xx., 1847, p. 391. 



