120 Green. — On Vegetable Ferments. 
exert diastatic powers on starch through excreting an enzyme 
when starch-grains are their only available food. Bacillus 
Amylobacter 1 breaks up cellulose by the same process, forming 
bodies which are soluble in water. According to Fitz and 
Hueppe 2 , the same bacillus excretes a rennet-enzyme when 
cultivated in milk. 
The most remarkable of these microbes is Bacillus mesen- 
tericus vulgatus , which Vignal 3 has shown to contain at least 
five separate enzymes ; diastase, invertase, rennet, a proteo- 
hydrolytic one, and one dissociating vegetable cells by destroy- 
ing the middle lamella. Though these all can be extracted 
from the microbe, the proportions vary much according to the 
culture-medium. 
The possession of several enzymes by the same cell seems 
at first rather strange, but we find the same thing in multi- 
cellular plants. Thus the germinating lupin-seed forms three 
enzymes in the cells of its cotyledons — rennet, diastase, and 
trypsin ; the castor-oil seed contains rennet, trypsin, and a 
glyceride-enzyme. All appear to originate in these two cases 
in the same cells. The animal organism also shows pepsin 
and rennet existing together in the peptic cells of the stomach, 
and three ferments in those of the pancreas. 
The cells of the cholera-bacillus, as mentioned above, behave 
very similarly to their enzymes with regard to their resistance 
to acids. They show a similar correspondence as to their 
optimum temperature for activity. 
The influence of the mode of cultivation on the microbe in 
the formation of the enzymes has been the subject of research, 
but no very complete investigation has at present been made. 
Flugge 4 has shown that if oxygen be prevented access to 
them during their growth, they do not excrete enzymes. 
A suggestion has been made by Wood, in his paper referred 
to above, as to the reason for the secretion of enzymes by the 
bacilli he examined. In the absence of such a secretion the 
1 De Bary, Lectures on Bacteria, p. 69 and 10 1. 2 Ibid. p. 104. 
3 Contribution a l'etude des bacteriacees (These pour le doctorat-es-sciences 
naturelles, Paris). 4 Die Micro-organismen, 1886, p. 470. 
