Dr. Oscar Loew 41 



from the pulp. The yeasts are chiefly Sac- 

 charomyces ell^psoide^ls and a certain amount 

 of S. apiculatus (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. 



