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 Stylopage preying on nematodes.
In Zopf's (11) account of the capture of nematodes by Arthrobotrys oligospora Fres. and Monosporidium repens Zopf were de? scribed, apparently for the first time, instances of a biological habit comparable in part to the carnivorous habit of insectivorous flowering plants. More recently (1, 2, 3) nearly a score of additional fungi occurring in soil, in leaf mold, and in solid decaying materials generally, have been found to capture and consume nematodes in large numbers; evidently, indeed, subsisting in nature entirely through such predacious activity. By far most of these fungi are closely related to those dealt with by Zopf, being referable to a group of interrelated genera including Arthrobotrys, Trichothecium, Cephalothecium, Dactylaria, Dactylella and Monacrosporium (4). The relatively few nematode-capturing forms alien to this hyphomycetous series are conidial phycomycetes belonging to the Zoopagaceae, a family whose known members are mostly destructive to terricolous amoebae, some operating in parasitic, others in predacious relationships (5, 6). Of the few species preying on nematodes, only one, Stylopage hadra Drechsl., has hitherto been described in detail (7) ; so that the description offered herein, of a second species of like biological habit, may be of interest even in the absence of pronounced departures in morphology. The fungus in question was obtained in quantity from several samples of soil collected by F. L. Wellman in celery fields near Sanford, Florida, January 1935. Pinches of the soil were placed on old maizemeal-agar plate cultures liberally infested with nema? todes representing species of Rhabditis, Cephalobus and Acrobeles. After a period varying usually from 1 to 3 weeks, vegetative my? celium was found present here and there in fairly extensive tracts. In general character this mycelium resembled that of Stylopage