THE BEGINNINGS OF LIFE. 58 1 



cites the following: — ^The wood of the American 

 locust-tree (Rol'mia), when grown in England, is nearly 

 worthless, as is that of the oak-tree when grown at the 

 Cape of Good Hope. 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. , . . It is well known that American varieties 

 of the apple produce in their native land magnificent 

 and brightly-coloured fruit, but in England of a poor 

 quality and a dull colour.' A^in, twenty-nine kinds 

 of American trees, belonging to different orders, have 

 been compared with their nearest European allies by 

 Mr. Meehan^, and have almost invariably been found 

 to differ from the latter in many similar respects, e.g. 

 in the leaves being less deeply serrated, whilst they fall 

 earlier and have a brighter tint, in the buds and seeds 

 being smaller, and in the trees being more diffuse in 

 growth. Mr, Darwin agrees with Mr. Meehan in 

 thinking that these differences must almost exclusively 

 have been ^ caused by the long-continued action of the 

 different climate of the two continents on the trees.' 

 Different climates also affect in a most marked 

 mannerj in the course of two or three generations, 



i ' Proc. Acad. Nat. Soc of Philadelphia,' Jan. 28, 1862. 



