26o introduction to plant geography [chap, 



Beverages and Flavours 



The major non-alcoholic beverages, although not as vitally essential 

 as the major foods, are yet so familiar that their significance is in 

 no need of explanation. They are tea, which is used by fully one- 

 half of the population of the world, coifee, which is used by almost 

 as many people, and cocoa — the ' beans ' affording this last also 

 yield chocolate and cocoa butter. Other beverages include mate or 

 Paraguay-tea, obtained from the leaves of various species of Holly ; 

 guarana, from the seeds of an Amazonian climber ; cola, obtained 

 by powdering Cola seeds ; khat, a tea-like drink of northeastern 

 Africa, and cassine, a rather similar beverage of North America ; 

 also yoco, which is made from the bark of a South American tree. 

 All these beverages contain some cafi^eine and consequently have a 

 stimulatory and refreshing eff"ect ; and numerous others are, or once 

 were, widely prepared from parts of various plants. 



Other non-alcoholic beverages are the so-called ' soft drinks ' 

 which include a vast array of preparations that tend to rise and fall 

 in popularity — more, perhaps, with the amount of advertising 

 lavished by their producers than with their inherent value, though 

 most contain a fair amount of sugar and so are a source of energy. 

 Many contain plant flavourings, etc., such as ginger, sarsaparilla, 

 malted Barley, wintergreen, cola, or fruit juices — the last constitut- 

 ing many popular and valuable drinks. 



Of alcoholic beverages there are two main groups : the fermented 

 ones in which the alcohol is formed by the fermentation of sugar, 

 and the distilled ones obtained by distillation of some alcoholic 

 liquor. The sugar is either present naturally, as in most fruit juices, 

 or is formed by transformation of starch — for example in cereals or 

 potatoes. Wines, of which there are almost endless types of varying 

 delectability and to suit difl^erent palates and pockets, are the oldest 

 and most important of the fermented beverages. They are mostly 

 formed by fermentation of sugar in the juice of grapes through the 

 activity of wild Yeasts present on the skins of the fruit, though a wide 

 range of other plants and their products may be similarly employed. 

 The agreeable aroma and flavour are due to the presence of various 

 aromatic substances, though the characteristic ' bouquet ' develops 

 only after some years or even decades of ageing. 



Beer, ale, and the like make up the other most important group 

 of fermented beverages. In their production, cereal starch (usually 

 in Barley) is transformed into sugar in the process of malting, and 



