The author provides additional data to his publication of 1955. In a table he shows his results concerning 81 algal species which were returned to the cave of Aggtelek on June 22, 1954. When carrying out his control tests he found the decrease in the number of species to be 9 after 6 months and 18 after a further 8 months. In December 1957, after culturing on sun light however he was able to show again the presence of 17 species, but in his cultures Synechoccus elongatus, Phormidium dimorphum, Gloecoccus schròterii, Chlorococcum infusionum, Chlorella miniata and Protococcus anulatus, appeared with the largest individual numbers and not the Cyanophyta as could have been expected.