The occurrence of Microsporon gypseum (Bodin, Guiart & Grigorakis) in soil nematodes
The author gives a brief survey on the prevailing statements of today's soil biology on the occurrence of nematodes in soils, further on their conditions of living and on those of the rapacious fungi as well. On the basis of his own investigations carried out mainly in garden soils of the Hungarian Plain being dressed and undressed with manure, he comes to the conclusion that the occurrence ofM. gypseum cultured by means of the To-Ka-Va method, and on the presence of the nematodes in the soil admit the assumption that the frequent infection of persons engaged in gardening which is generally caused byM. gypseum, is likely to be in correlation with the abundance of nematodes in these soils.
Some Hyphomycetes that Prey on Free-Living Terricolous Nematodes
In several preliminary summaries (12, 13, 14) published a few years ago, were set forth synoptical ly the morphological features of 16 fungi observed to subsist by the capture of free-living nematodes infesting old agar plate cultures started from various decaying plant materials. Little attention was then given to the relationships of the different fungi to species previously described, only one among them, the widely familiar and well characterized Arthrobotrys oligosfora Fres., whose predacious behavior had been impressively recorded by Zopf (72) nearly a half century earlier, being mentioned by name. In a subsequent paper (15), consideration of special organs developed by nematode-capturing ftmgi entailed identification of two other of the 16 forms; one being recognized as Dactylaria Candida (Nees) Sacc, the other as Dactylella ellipsospora Grove. The remaining 13 fungi, with the exception of two species belonging in the Phycomycetes, could be referred to (16, 18, 20) only rather cumbersomely as members of an interrelated series of Hyphomycetes distributed in large part among the genera Trichotkecitim, Arthrobotrys, Dactylella (including Monacrosporium), Dactylaria and Pcdilospora. Although some of the mucedinous forms known to capture nematodes are dealt with under established binomials, usage regarding these binomials has not always been consistent. The
A new species of conidial Phycomycete preying on nematodes.
Although the Zoopagaceae hitherto observed in Petri dish cultures started from decaying plant materials consist preponderantly of forms destructive to Amoebae, at least several fungi undoubtedly referable to the same taxonomic group have been found that evidently subsist entirely by capturing and consuming nematodes. Of these several fungi the one whose morphology and predacious habit were briefly set forth in the text and synoptic illustrations of an earlier summary (1, p. 140, lines 6 to 13; p. 139, fig. 8, A, C) has made its appearance by far most frequently. In the vicinity of Washington, D. C., it seems to be present on leaf mold wherever in parks on other wooded tracts this material has had opportunity to accumulate in deposits deep enough to retain some moisture during periods of dry weather. When a pinch of leaf mold from such a deposit is added to an agar plate culture already well infested with nematodes, the fungus develops with considerable regularity, giving rise within 5 to 15 days to a growth, which, if ordinarily too scanty to be readily noticed with the naked eye, is fairly conspicuous under a microscope of low magnification.