CLASSIFICATION OF ANGIOSPERMS. 327 



of Brazil has been used as a substitute for cinchona. A number 

 of genera furnish fish poisons, as Zizyphus, Tapura, and Gouania. 

 Gum-lac is formed on the twigs of Zizyphus Jiijuba of Asia as 

 the result of the sting of an insect {Coccus lacca). 



The fruits of several species of Zizyphus, thorny shrubs found 

 growing in South America, are edible and enter into the French 

 or Spanish confection known as Jujube-paste. 



b. VITACE^ OR GRAPE FAMILY.— The plants of this 



family are woody climbers or erect shrubs with alternate, petiolate 



•leaves, and small, greenish, regular flowers, the fruit being a berry. 



The most important genus, economically, is Vitis to which 

 belong the cultivated grapes, the fruits of which furnish raisins, 

 wine and brandy. The grape-vine indigenous to Europe {Vitis 

 vinifera) is cultivated in all temperate and sub-tropical countries, 

 and the variety silvestris which is found distributed in the Medit- 

 erranean countries as far east as the Caucasus Mountains is sup- 

 posed to have furnished the cultivated wine grape. The Concord 

 and Catawba grapes are cultivated varieties of the northern Fox- 

 or Plum-grape {Vitis Labrusca) indigenous to the Northern 

 United States east of Minnesota. The Delaware grapes are cul- 

 tivated varieties of the frost-grape {V. cordifolia) and the sweet- 

 scented grape {V. vnlpina) of the Eastern United States. The 

 pulpy part of the grape contains from 9 to 18 per 'cent, of grape- 

 sugar and 0.5 to 1.36 per cent, of tartaric acid. In unfavorable 

 seasons the tartaric acid is replaced in part by malic acid. The 

 soil has a marked influence on the quality of grapes, a sandy soil 

 producing a light colored wine, a soil rich in calcium a sweet 

 wine, and a clay soil a fine boquet, etc. 



Wines are made by fermenting the grape juice, and contain 

 from 5 to 20 per cent, of alcohol, from i or 2 to 12 per cent, of 

 sugar, about 0.5 per cent, of tartaric, acetic and other fruit-acids, 

 tannin and coloring matter from a trace to 0.3 per cent., and 

 various compound ethers, giving them their characteristic flavors 

 or boquets. White wines are made from the juice of the pulp 

 of the white or colored grapes after separation from the epicarp 

 and seeds. In the manufacture of red wine no care is taken to 

 separate the seeds and skins of colored grapes or even the stems 

 on which the fruits are borne. Port wine is made from a grape 



