Kaszab Zoltán (szerk.): A Magyar Természettudományi Múzeum évkönyve 63. (Budapest 1971)

Gönczöl, J.: Aquatic Hyphomycetes from the Mts. Börzsöny

Fig. 2. Accumulating foam in the Morgó-brook essentially more than by collecting with a plankton net, the approved tool of the algologists. According to my experience, this latter is wholly unsuitable for collecting the conidia of aquatic Hyphomycetes—even when filtering away many hundred liters of water, only one or two spores could be found and those, too, of the most common species. Quantitative examinations were made only from the natural froth. The floating foam was skimmed with a plastic container of wide mouth, taking care to lift out as little water as possible. Frozen ice could of course be gathered simply enough. The foam collapses only slowly, hence I enriched it by shaking and beating the sides of the vessel. The collapsed foam turns in general into a yellowish grey, opalous liquid; 100 ml. served for the quantitative investigations. Of this material, the conidia and other floating substances (algae, organic and inorganic matter) sedimented in a few hours. The number of spores fluctuated between 6,000 — 10,000 (ml. in the sediment). The sample can be stored without any treatment for about a week in a refrigerator. After this time, the greater part of spores deteriorate strongly, becoming unsuitable for examination. Conserving in alcohol and formaline were first found to be unsuitable, and the conidia of the aquatic Hyphemycetes became destroyed in both media. NILSSON (1964) reported on similar experiences. In later attempts, 2 — 3 drops of 37% formaline, if added in a previously soluted form to the sample, preserved the conidia in good state. Microscopic examinations were made, as far as possible, on fresh, live material taken from the sample, usually by a phase contrast instrument. Discussion of the species found (Fig. 3) In the course of investigating the Morgó brook for a year, I identified 20 species of 16 genera of the aquatic Hyphomycetes, as follows.