SOIL ALGAE 235 



the soil. Algae also exert a solvent action upon insoluble calcareous 

 materials (Chodat). In this respect, algae together with certain auto- 

 trophic bacteria play an important role in the disintegration of rocks 

 and in the formation of soils. The possible role of algae in the 

 deposition of limonite has also been suggested. 61 



61 Steinecke, F. Limonitbildende Algen der Heide-Flachmoore. Bot. Archiv, 

 4: 403-405. 1923. 



