A new limnological method for the investigation of thin-layered epilithic communities

Abstract

The study of thin-layered algal communities has always been a very difficult and troublesome one. Different authors (BuTCHER 1932, IVLEV 1933, GODWARD 1934, 1937) have introduced the use of glass slides, which, after remaining a time under the water, are picked out again and microscopically investigated. The method is not suitable for an extensive survey of a very large country rapidly travelled. Moreover, it is very likely that the communities that become fixed upon the slides may be different from those found in natural biotopes. It is a pressing need to find a more suitable method for the research of those thin layered communities. I have obtained very satisfactory results in the application of a method suggested by BUSCALIONI and POLLACCI (1901, quoted by WENZL) and developed by WZNZL (1940, 1941) for the research of superficial topography of leaves and epiphytic fungi. The "collodium-film" method has been used too by the author in the study of soft tertiary lacustrine sediments. The modus operandi for the study of epilithic communities is as easy as efficient, and will be described in the following lines