SECRETION OF DIASTASE BY PENICILLIUM CAMEMBERTII 245 
not formed, save when starch was the source of carbon, in which case 
the enzyme was found only in the myceHum. Saito concluded that 
the source of nitrogen is significant in the formation of diastase. 
Stoward (1911) grew barley embryos for from four to eight days 
in gelatine, and found that a mixture of asparagin and mineral salts, 
consisting of CaS04, KCl, MgS04, KH2PO4, and FeCU, influences 
the secretion of diastase more favorably than either the asparagin or 
the mineral salts alone. After determining the effect of the mineral 
salts on the activity of the secreted diastase, he concludes that they 
enter in some way into the metabolism of the embryo and thereby 
influence its secretory function. 
Javillier (1912) noted that Aspergillus niger, grown in Raulin's 
solution lacking zinc, secreted invertase sufficiently rapidly to invert 
saccharose, but that the quantity secreted, calculated per unit of dry 
weight of the fungus, was noticeably less than was produced by the 
fungus in a complete solution. 
Euler and Meyer (191 2) suspended yeast cells in solutions of 
various substances for times varying from 20 to 150 hours, filtered 
off the yeast, and determined the inverting power of a unit weight of 
this living yeast. They found that by suspending the yeast in a solu- 
tion of 4 g. of asparagin, glycocoll, or ammonium sulphate in 500 cc. 
of Lintner's solution, the effect on the formation of the enzyme inver- 
tase was beneficial and the same in each case. 
Euler and Cramer (1913), working with the same problem, state 
that invertase formation is clearly bound up with the new formation 
of protoplasm. The building up of protoplasm, however, is dependent 
on, first, the fermentation that supplies energy, and second, the 
presence of suitable nitrogenous material in the medium. When the 
solution used in the treatment of the yeast contains no nitrogenous 
material, invertase formation occurs, but in slight amount. 
It is evident that information on the problem of the influence of 
inorganic salts on enzyme secretion is extremely meager. 
The Effect of Single Salts on the Digestion of Starch by 
PeNICILLIUM CAMEMBERTII 
The effect of the chlorides, the sulphates, the dihydrogen phos- 
phates, and the nitrates of sodium and potassium, and of the chlorides, 
the sulphates, and the nitrates of calcium and magnesium, when 
