Szekessy Vilmos (szerk.): A Magyar Természettudományi Múzeum évkönyve 53. (Budapest 1961)

Halász, M.: The microvegetation of the acrothermae of Harkány

of the cells, Geitler relegated it to a distinct family : Cyanidiaceae n. fam., assigning it to the Chamaesiphonales group (Arch. f. Hydrobiol., Suppl. 12, 1933, p. 624), and describing it as Cyanidium n. genus and n. species. According to Geitler, the species, found by Ruttner in the solfataras of Central Sumatra (Arch. f. Hydrobiol., Suppl. 14, p. 389), is indubitably identical with the algal species collected by J. E. Tilden (Yellowstone Nat. Park, Wyoming : Frying Pan basin, July 1896), and described as Protococcus botryoides f. caldaria Tilden, in his paper : Observation on some West American Thermal Algae, in 1898 (Bot. Gaz., 25, 1898, p. 94, Pl. 8, f. 18 ; Bot. Gaz., 25, 1898, p. 104, Pl. 8, f. 21). Setchell (in Collins, Holden&Setchell, Phyc. Bor. Amer., 18, No. 851, 1901) described the same species as Pleurocapsa caldaria (Tilden) Setchell, though, contrary to the Pleurocapsaceae, the cells lack the f

ilamental structure. Owing to this latter characteristic, F o r t i (in De Toni, Syll. Alg., 5, 1907) places it among the insufficiently described species. Tilden (Minnesota Algae, Minneapolis, 1910) lists it from collectings originating from the geysers of the Yellowstone Park (W e e d 1897) ; Seto h e 11 cites it from California ("Devil's Kitchen" Geyser, Sonoma County, June 1900). Copeland described it also from the geyers of the Yellowstone Park, by the name Pluta caldarius Copeland (Copeland 1936). With respect to the description of the species, Geitler (Arch. f. Hydrobiol., 1936, p. 369) remarks that the cells are morphologically analogous with some Chlorella species and it is possible that it is a monocellular organism possessing a chromatophore and a nucleus, and thus, according to him, belonging to the unicellular organisms allocated to the Bangiaceae. I found the thermal organism, known hitherto mainly from America (Weed 1897, Tilden 1898, Copeland 1936), North Sumatra, Java (Geitler&Ruttner 1936), and the hot springs of Japan (Beppu) (Y. O k a d a, Ecol. Rev., 5, 1939, p. 260. f. A

t

, and Y. Y o n e d a, Acta Phytotaxonom. et Geobot., 1940, p. 40), on the wall wet from the warm vapours of the mud basin in the thermae of Harkány, forming a coating due to its mass occurrence. On the basis of my observations, its classification as a Cyanophyta, due to its strikingly different morphological properties and in spite of its bluish green color, was rather dubious. I found the correctness of my assumption substantiated by M. B. Alle n's (1954) investigations, who established by profound experiments, on materials isolated and in culture from the typical locality, that this organism, described and relegated to the Cyanophyta by Geitler, Copeland&Drouet independently of each other, is monocellular, possessing a chromatophore, and thereby uniting in itself the cellular structure characteristic of the Chlorophytae, that is, it was found to be an organism having a chromatophore and a nuclear structure. F. D r o u e t & W. A. D a i 1 y (Butler Univ. Bot. Studies, 12, 1956) regard the type described by Tilden, on the basis of their examination of the original specimen, as an organism belonging also to the Chlorophyta, namely a Chlorella. According to the recent studies of H. H i r o s e, this thermal organism should systematically be relegated to the Bangiales, as, besides its nuclear structure, it contains only chlorophyll-a and phycocyan, but no starch (H i r o s e, Bot. Mag., Tokyo, 71, 1958, p. 347 ; G e i 1

1 e r, Ö. B. Z., 106, 1959, p. 172). And as far as the occurrence of the organism with respect to pH is concerned, Alle n's experiments showed, in contrast with the earlier observations which maintained that