1922] CURRENT LITERATURE 507 
Pigment development in Cyanophyceae.—BoreEscn™* finds that as cultures 
red, red brown, or even yellow brown. e addition of a small amount of 
iron salts leads to the return of the original color in a few days in diffuse light. 
These changes can be repeated in a given culture at pleasure. The author 
believes this is the first case of iron chlorosis reported for algae, although a 
number of cases have been reported in higher plants under practical growth 
conditions. In the young cultures there is much of a red violet water soluble 
protein pigment with a Venetian brown fluorescence along with much chloro- 
phyll and carotin. As the color changes with iron deficiency, the carotin 
remains undiminished, but the other two pigments largely disappear. 
The author states that it was known already that aside from species 
characters, the main conditions that have interested investigators in pigment 
development i in the blue green algae are N-chlorosis, which is very likely to 
of light. In monochromatic light there is a change in the quantity of phyco- 
cyanin, and in full sunlight there is a great diminution in the amount of both 
chlorophyll and phycocyanin.—W. CROCKER. 
Use of nutrient salts of low solubility—The value of certain relatively 
insoluble salts as sources of necessary ions for the growth of seed plants has 
been tested by DuGGar*® in a variety of combinations, but by no means 
covering the entire range of possibility. It is argued that in certain types of 
work many advantages may accrue from the use of combinations of insoluble 
salts, because of the tendency to maintain a constant concentration of the 
various ions furnished, and also because no renewal of the solution (except 
as to addition of NO;) is required from day to day. In each of three cultures 
in which wheat or wheat and corn were used, one or more of the combinations 
containing two or more insoluble salts exceeded the growth in the best control 
culture employed. Soluble ferric phosphate, and in certain cases ferric citrate, 
proved very valuable. The reason for the marked beneficial action of these 
is not yet determined. In most cases in these experiments the Pz lay between 
5.6 and 8.0, and with growth the Px shifted somewhat toward alkalinity. — 
Wa. CROCKER 
Life history of a Pezizella—SHEAR and Dopce* have uncovered an 
interesting life history of an Ascomycete, and have illustrated the present 
24 Borescu, K., Ein neuer die Cyanophyceenfarbe bestimmender Faktor. Ber. 
Bot. Gesells. 38: 286-287. 1920. 
2 Duccar, B. M., The use of “insoluble” salts in balanced solutions for seed 
plants. Ann. Mo. Bot. Gard. 7:307-327. 1920. 
2% SHEAR, C. L., and Doncg, B. O., The life history and acinatity of “ Patellina 
Fragariae,” “ Leptothyrium macrothecinm,” _and ‘‘ Peziza oenotherae.’’ Mycologia 13: 
135-170. pls. 8-10. 1921. 
