NON-ALCOHOLIC BEVERAGES 



155 



Fig. 150, I. — Coffee. Fruit, cut across to show the two seeds (the "coffee 

 beans" of commerce). Same, with lower part removed to show posi- 

 tion of the embryo. (Baillon.) 











a 



Fig. 151. — Yeast (Saccharomyccs cerevisice, Yeast Family, Saccharomyctta- 

 cece). a, a single becr-yeast plant; groatlj' magnified; h, same sending 

 forth a bud-like protrusion; c, same with bud more developed and a 

 second one appearing; d, a colony produced by such budding without 

 separation; e, a yeast plant divided into four within the enveloping 

 wall ; /, a plant dividing into two, each with a wall of its own, and thus 

 able to resist adverse conditions for a long whUe; g, a cluster of four 

 such resistant plants, one of which upon the return of favorable con- 

 ditions is producing a budding colony; h, such a colony farther ad- 

 vanced. (Luerssen, Reese.) — Beer yeast, the form here shown — 

 used not only for beer but for bread — is not found wild; but the closely 

 similar wine yeast occurs regularly upon the surface of grapes and (in 

 its resistant form in the soil of vineyards) so does not have to be added 

 to the grape "must" in making wine. The plant is very pale brown 

 or colorless. 



Fig. 152. — -Vinegar Ferment (Bacterium aceti, Rod-germ Family, Bacteria- 

 cece). a, ordinary form of plant, grouped into chain-like colonies, ^{^^ 

 h, an irregular form occurring under very adverse conditions. (Migula.) 

 — The plants are colorless, and form about themselves a mass of jelly 

 which constitutes the "mother" of vinegar. 



