Dr. Oscar Loew / 4! 
from the pulp. The yeasts are chiefly Sac- 
charomyces ellipsoideus and a certain amount 
of S. apzculatus (see also p. 62, re “ Coffee 
Ferments”), which develop rapidly. These 
organisms occur on fruits, as well as in the 
dust of the air and on the surface of the soil, 
together with numerous bacteria. The alcohol 
formed in the fermentation of the sugar from 
the pulp by these yeasts kills the cells of the 
superficial strata of the pulp or slime tissue, 
and as its juice passes freely to the outside, 
nourishment is given to innumerable bacteria, 
among them the widely distributed acetic 
bacillus. The respiration of these organisms 
and the fermentative activity generate heat, 
and gradually a considerable elevation of tem- 
perature is reached. 
The juice on the surface now assumes a 
strong acid reaction, due to the oxidation of 
alcohol to acetic acid, and this suffices to 
destroy the remaining cells of the slime layer, 
causing thereby a considerable shrinkage of 
it, and also a further discharge of juice, as 
the cytoplasm of the dying cells becomes 
permeable to the interior juice. Thus a 
considerable amount of liquid gathers at the 
bottom of the receptacles and, since this liquor 
has an agreeable sour smell and taste, it is 
used in some factories as vinegar. By the 
bacterial action the attached pulp is further 
loosened from the testa to some extent and 
can be washed away, as is done in Ceylon. 
