464 PKACTICAL BOTANY 



grapes upon this introduced stock. The grape industry of 

 France has been greatly increased by thus growmg French 

 grapes upon the stronger and more productive American stock. 

 Some French grape growers, still believing that the quality 

 of their grapes would deteriorate if grown upon American 

 stock, use carbon disulphide as a means of protection against 

 phylloxera, but this treatment is still too expensive to be 

 used in the ordinary vineyards. 



429. Garden vegetables. Another group of plants which form 

 the basis of a great industry includes those generally known 

 as vegetables. The vegetables come from many plant families. 

 Accordmg to one authority,^ there are at least two hundred 

 eleven distinct species of garden vegetables, and many of these 

 species are represented by very large numbers of varieties. The 

 parts of these plants u.sed as food may be the roots (sweet 

 potato, radish, etc.), the combined stem and root (beet, parsnip, 

 carrot), the underground stem (white potato, Jerusalem arti- 

 choke), stem and leaves (lettuce, cabbage), and the fruit (to- 

 mato, squash, cucumber, eggplant, string beans). The list of 

 vegetables is too long and varied for any common characters 

 to be given for it. 



1 Vilmorin, in The Vegetable Garden. 



