Two coccus-form species of blue-green algae havebeen isolated in species-pure culture and cultivated ona number of solid and liquid media. For one species, amedium of strictly-known composition has been developed.
The principal characteristics of the process ofassimilation in these algae have been studied by themanometric method. The process is essentially like thatin other green plants. The shape of the curve relatingassimilation to light intensity gives an indication thatthe blue-pigment of the Cyanophyceae does not take part in photosynthesis.
A study of the relation of the color of a blue-greenalga to environmental conditions shows that the colordepends principally on the chemical constitution of themedium and the intensity of incident light. Temperatureand light color may have minor effects.
