250 GENEBAL BOTANY 



Beer and wine making. In the making of beer and wine the 

 ferments and the processes involved are identical with those 

 just described for bread making. The difference in the final 

 practical result is that in beer and wine making the alcohol is 

 saved and the carbon dioxide is largely allowed to escape. 

 The sugar for the fermentative process may be supplied directly 

 or it may be obtained from sprouted barley (called malt), from 

 expressed grape juice, or from the juices of other fruits. The 

 special flavors of different wines and beers are due in part to 

 the kind of yeast plants used and in part to the source from 

 which the sugar solution is derived. 



In the preparation of malt from barley the grain is first 

 sprouted, in order that the stored starch of the barley seed 

 may be digested and so transformed into a cane sugar. This 

 digestion is due to the secretion of digestive ferments by the 

 storage cells of the seeds. The cane sugar (maltose) thus formed 

 is dissolved out in water from the dried and crushed seeds, and 

 furnishes the sugar for the action of the beer yeasts. These yeasts 

 then transform the cane sugar into grape sugar, and this again 

 into alcohol and carbon dioxide, exactly as described above in 

 bread making. 



The great value of the yeasts in the industries is due to the 

 rapid reproduction of the yeast cells by budding, and to the 

 peculiar nature of the secreted ferment, which is able to trans- 

 form large volumes of sugar into alcohol and carbon dioxide 

 without losing its active properties. 



BACTERIA 



Bacteria are plants of the greatest interest and importance 

 to man on account of their relation to disease, to the destruc- 

 tion of food, and to the maintenance of certain modern indus- 

 tries. It is not generally known that bacteria, as well as yeasts, 

 are plants which belong to the great group of fungi which we 

 are now studying. Botanists classify them as fission fungi, or 

 Schizomycetes, on account of their mode of multiplying by simple 

 cell division, or fission. They are derived, like the yeasts, from 



