136 Green. — On Vegetable Ferments. 
from yeast and at least two of the fungi, Fusarum and 
Aspergillus , invertase has been extracted ; from Aethalium a 
proteo-hydrolytic ferment has been obtained ; from more than 
one fungus a cytohydrolyst has been prepared. Though the 
alcoholic ferment has not been extracted from the yeast-plant, 
this proves to be no peculiar property of that plant, as it can- 
not be isolated either from the fruits in which the formation of 
alcohol occasionally occurs. 
Nor is there the radical difference in the nature of the 
products formed which Nageli maintained. Boehm 1 and De 
Luca 2 have shown that if any part of a living plant he in- 
sufficiently supplied with oxygen, hydrogen, and sometimes 
marsh-gas are evolved from it Boussingault 3 and Schulz 4 
have observed similiar phenomena. From plants containing 
mannite also hydrogen is given off, while according to De 
Luca 5 acetic acid is formed from malic acid in the fruits, flowers, 
and leaves of the Privet. In the decomposition of proteid 
too Boehm 1 found ammonia exhaled. The condition under 
which these results are obtained, viz. the lack of oxygen, is 
the normal condition of many of the microbes, they being 
anaerobiotic in their mode of life. When oxygen is present 
we find the same agreement. The result of the action of in- 
vertase is the same, whether that action be brought about by 
living yeast, or by invertase extracted from a higher plant. 
The decomposition set up by trypsin, in the formation of 
albumoses, peptones, and amide-bodies, is similar to that 
induced by some of the proteo-hydrolytic bacteria. Sachs 
claims as a peculiarity of all fermentation set up by fungi that 
C0 2 appears as a bye-product 6 . This however we have seen 
to be rather an effect brought about by an insufficient supply 
of oxygen, and easily made evident under the same condition 
in the fermentative actions of the protoplasm of the higher 
plants also. We can see therefore that in both lower and 
1 Boehm, Sitzgber. d. k. Akad. d. Wiss. in Wien, LXXI, 1875. 
2 De Luca, Ann. d. Sc. Nat. Ser. 6, VI, 1878. 
3 Boussingault, Agronomie, t. iii, 1864. 
4 Schulz, Journ. f. Prakt. Chem. LXXXVII, 1862. 
s Sachs, Physiology of Plants, Engl, transl., 1887, p. 349. 
5 loc. cit. 
