236 VEGETABLE SUBSTANCES. 



quince was introduced into England and Holland 

 nearly forty years ago, and was planted in France 

 about ten years later. The tree has much the ap- 

 pearance of the common quince, as well as the fruit. 

 It is remarkable for the number and brilliancy of its 

 flowers. 



ORNAMENTAL CRABS. 



The crab of Siberia, which had been introduced 

 into this country within the last fitty years, has 

 contributed to the extension of our varieties of 

 apple, by offering a valuable stock for grafting. 

 The fruits thus produced by the union of our 

 richest apples and the Siberian crab are remark- 

 ably hardy and luxuriant. The Siberian crab dif- 

 fers in a peculiar manner from our native crab. It 

 furnishes one of the many evidences of the con- 

 tinued influence of original climate upon vegetables, 

 when they are naturalized in another region. The 

 winters of Siberia are intensely cold, the change to 

 summer is sudden, and the heat equally violent. 

 Our own changes of temperature are much slower, 

 and more irregular. Thus, when the native crab 

 scarcely shews signs of life, the Siberian variety puts 

 forth its leaves, blossoms, and bears fruit, early even 

 in an unfavourable season.* The flowers of the 

 Siberian crab are beautiful; and its fruit is of a sharp, 

 yet pleasant, flavour. There are many pretty va- 

 rieties of PyrtUj which are principally cultivated in 

 our gardens for their flowers. The Chinese crab 

 (Pyrus spectabilis} is most showy and ornamental. 

 It grows to the height of twenty or thirty feet. Its 

 blossoms are of a pale red, but they are of short 



* See Hort. Trans., vol. i. 



