Studies in Mycology No. 4

Variability in Mucor hiemalis is demonstrated by mating experiments and morphological studies of a great number of strains. It is concluded that M. hiemalis, M. luteus, M. lausannensis, M. silvaticus, M. corticolus and M. vallesiacus ought to be classified in a single variable species: M. hiemalis. Accepted formae are: M. hiemalis f. hiemalis, M. hiemalis f. silvaticus, M. hiemalis f. corticolus and M. hiemalis f. luteus. M. genevensis is the homothallic counterpart of M. hiemalis. Descriptions and figures of the species and formae and a key are given.