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 fungus parasitic on nematodes.
In the summer of 1931 the writer decided to make a final examination of certain fungi that had developed in a moist chamber in which a batch of strawberry plants had been kept for about three weeks. In the material, his attention was attracted by a fungus with conidia-like bodies having the form of complete, hyaline rings (plate 35, figs. i, g, n). The thickness of the hypha in the rings was considerably greater than that of the simple, septate branches on which they were produced. The content of the rings was also more dense than that of the hyphae even at the early stages of their growth; later on the branches were observed to be practically void of protoplasm. In some mounts rings both attached to the mycelium and detached were observed in considerable numbers. The detached rings were without any remnants of the hyphae (plate 35, fig. n). Thus they were plainly differentiated from the mycelium and ap? peared to answer our usual conception of conidia; they are here considered as such. In most cases the septation was indistinct or absent in the rings (plate 35, fig. n) ; however, infrequently the septation was quite clearly observed (plate 35, fig. i). On further examination of the fungus it was found to produce other differentiated bodies, from globular to oval in shape (plate 35, figs. e and h), on branches similar to the conidiophores terminating with the rings. These resemble young terminal chlamydospores so common in some species of Fusarium. Besides these two no other differentiated bodies were observed; and from the beginning it was suspected that the globular bodies were the first stage in the development of the ring-shaped conidia, even though it was not easy to visualize the process of develop? ment from the first to the second stage. However, in the mate? rial observed this year it was found that the globular bodies at a certain time send out a somewhat pointed tube which, as it 258