Fig. 3

Analysis of structure of dendrolitic cone filament. a Scanning electron microscopy images from an individual dendrolitic cone filament, pre-(left) and post-(right) treatment with one drop of 1 M HCl to remove calcium carbonate. b, c Grains intertwined between filamentous microorganisms, prior to treatment with 1 M HCl. d, e Post-treatment observation of voids