Barium accumulation by desmids of the genusClosterium(Zygnemaphyceae)

Abstract
By means of X-ray analysis with a stereo-scanning electron microscope, it has been demonstrated that the crystals enclosed in the terminal vacuoles of several species of the desmid genus Closterium are of barium and not calcium sulphate as previously reported. Barium sulphate has also been found in cells of Pleurotaenium and Micrasterias.