Cytological studies on the zygospores of Sporodinia grandis

Abstract

In recent years much interest has been aroused in the cytology of the lower fungi, and considerable work has been done upon these forms. While various members of different groups have been studied, the most definite results have been obtained in the Entomopthorineae and the Oomycetes. Although several of the Mucorineae have been worked out, more or less thoroughly, the results obtained by the different investigators, have been, to some extent, contradictory. As a result some uncertainty still exists with regard to the internal processes connected with sexual fusions. Further investigation seems, therefore, to be desirable, and the present study was undertaken for the purpose of adding something, if possible, to our knowledge of these internal activities. In as much as Sporodinia grandis is an abundant and wideIy distributed form among the Mucorineae, it has furnished since earliest times a particularly favorable form for investigation. It is easily obtained since it grows, parasitically, on many of the higher fungi, e.g. the Agarics; moreover, it can be obtained readily in cultures on various media. Here the zygospores are produced abundantly. The sexual hyphae arise from the same mycelium, and in many cases from the same dichotomy, and the zygospores are borne on aerial branches. This habit of growth makes it possible to obtain all stages of copulation.