NON-ALCOHOLIC BEVERAGES 155 
Fic. 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.) 
Fig. 151.—Yeast (Saccharomyces cerevisie, Yeast Family, Saccharomyceta- 
cee). a, a single beer-yeast plant; greatly magnified; b, 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; f, a plant dividing into two, each with a wall of its own, and thus 
able to resist adverse conditions for a long while; 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- 
cee). a, ordinary form of plant, grouped into chain-like colonies, +4°°; 
b, 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. 
