264 DEFINITE ACTION OF THE Chap. XXIII. 



retains its character as long as grown in a dryish soil, but soon 

 loses it when planted in fresh and humid soil. Mr. Salter, who is 

 well known for his success in cultivating variegated plants, informs 

 me that rows of strawberries were planted in bis garden in 1859, in 

 the usual way : and at various distances in one row, several plants 

 simultaneously became variegated ; and what made the case more ex- 

 traordinary, all were variegated in precisely the same manner. These 

 plants were removed, but during the three succeeding years other 

 plants in the same row became variegated, and in no instance were 

 the plants in any adjoining row affected. 



The chemical qualities, odours, and tissues of plants are often 

 modified by a change which seems to us slight. The Hemlock is 

 said not to yield couicine in Scotland. The root of the Aconitum 

 napellus becomes innocuous in frigid climates. The medicinal pro- 

 perties of the Digitalis are easily affected by culture. As the PUtacia 

 hntiscus grows abundantly in the South of France, the climate must 

 suit it, but it yields no mastic. The Lauras sassafras in Europe 

 loses the odour proper to it in North America. 11 Many similar facts 

 could be given, and they are remarkable because it might have been 

 thought that definite chemical compounds would have been little 

 liable to change either in quality or quantity. 



The wood of the American Locust-tree (Bobinia) when grown in 

 England is nearly worthless, as is that of the Oak-tree when grown 

 at the Cape of Good Hope. 1 - Hemp and flax, as I hear from Dr. 

 Falconer, flourish and yield plenty of seed on the plains of India, 

 but their fibres are brittle and useless. Hemp, on the other hand, 

 fails to produce in England that resinous matter which is so largely 

 used in India as an intoxicating drug. 



The fruit of the Melon is greatly influenced by slight differences 

 in culture and climate. Hence it is generally a better plan, 

 according to Naudin, to improve an old kind than to introduce a 

 new one into any locality. The seed of the Persian Melon pro- 

 duces near Paris fruit inferior to the poorest market kinds, but at 

 Bordeaux yields delicious fruit. 13 Seed is annually brought from 

 Thibet to Kashmir, 14 and produces fruit weighing from four to ten 

 pounds, but plants raised next year from seed saved in Kashmir 

 give fruit weighing only from two to three pounds. It is well known 

 that American varieties of the Apple produce in their native 

 land magnificent and brightly-coloured fruit, but these in England 

 are of poor quality and a dull colour. In Hungary there are many 



11 Engel, ' Sur les Prop. Medicales ' Gardener's Chronicle,' 1849, p. 355 ; 



des Plantes,' 1860, pp. 10, 25. On 1862, p. 1123. 

 changes in the odours of plants, see 12 Hooker, ' Flora Indica,' p. 32. 



Dalibert's Experiments, quoted by l3 Naudin, ' Annales des Sc. Nat.,' 



Beckman, ' Inventions,' vol. ii. p. 344; 4th series, Bot, torn, xi., 1859, p. 81. 



and Nees, in Ferussac, ' Bull, des Sc. 'Gardener's Chronicle,' 1859, p. 464. 

 Nat.,' 1824, torn. i. p. 60. With > 4 Moorcroft's 'Travels,' &i ., vol 



respect to the rhubarb, &c, see also ii. p. 143. 



