1914] CURRENT LITERATURE 161 
compounds by fungi, WATERMAN? has applied the conceptions of “‘plastic equiva- 
bon dioxide. Experimentally these relations are obtained by determinations of 
the carbon given off in respiration, the quantity fixed in the body of the fungus, 
and the total quantity that has been consumed. 
The author has studied from this point of view the assimilation of glucose, 
levulose, mannose, and a number of organic acids. As a rule, however, only 
the plastic equivalents were determined, the respiratory equivalent having been 
determined only for succinic acid. The results show, apparently to the mild 
Surprise of the author, that the plastic equivalent is high during the early 
Stages of growth, and falls with increasing age of the culture; while the greater 
Part of the carbon nutrient disappears during the first few days of growth. 
From these observations he arrives at his main conclusion, that the temporary 
accumulation of carbon in the fungus is due to the formation of an intermediate 
product which he finds to be glycogen. This view, of course, presents nothing 
novel, for it is well known that in the presence of an excess of food, reserve 
materials, which in fungi mostly take the form of glycogen, are stored in the 
plant body, and that respiratory activity, decreasing the “plastic equivalent,” 
continues at the expense of reserve materials and even at the expense of pro- 
teids when the external food supply has been exhausted. All such substances 
must in this sense be regarded as intermediate products. In this connection 
it may be pointed out that from the discrepancy between the quantity of 
carbon dioxide developed by a fermenting mixture and that which should have 
been developed according to the quantity of glucose (determined by change in 
rotation) which disappeared from the mixture, EULER and JouaNsson® have 
recently concluded that intermediate products were first formed from the glu- 
Cose in the process of fermentation. Regarding the author’s method it should 
also be stated that SPIEKERMANN,! without giving special names to the ratios, 
determined for a species of Penicillium growing on glycerin the percentage of 
the consumed carbon fixed in the plant body, and that given off in respiration. 
Finally, WaTERMANN has investigated the influence of various factors in 
relation to the plastic equivalent. Changes in temperature and in concentra- 
Hon of the nutrient medium do not influence the nature but only the rate of 
tty 
_ ‘WATERMAN, H. I., Beitrag zur Kenntnis der Kohlenstoffnahrung von Aspergillus 
miger. Folia Microbiol. 1:422-485. 1913. 
> Euter, H., und Jonansson, D., Umwandlung des Zuckers und Bildung der 
Kohlensiure bei der alkolischen Garung. Zeitschr. Physiol. Chem. 76: 347-354. 1912. 
' a. , A., Die Zersetzung der Fette durch hdhere Pilze. Zeitschr. 
ee, oe - Nahrungs- u. Genussmittel 23: 305-331. 1912. 
