Three Acidophilic Volvocine Flagellates in Pure Culture*

SYNOPSIS. Three acidophilous volvocine flagellates from peat water in Czechoslovakia were obtained in pure culture by the washing technique. Two of these, Carteria acidicola and Chlamydomonas acidophila , grew so densely in low‐pH Euglena gracilis media containing glutamic acid as to suggest they possess a vigorous heterotrophy. The other, Carteria turjosa , grew less well and required vitamin B 12 . In peat‐water media the upper limit of growth was 5.5. The lowest pH tested, 2.5, permitted growth of Carteria acidicola and Chlamydomonas acidophila. Some peptone media permitted growth at pH 6.0. The morphology of these flagellates is described.