THE MOULD-FUNGI. 



113 



again able to develop the mould-form. The mycelium pro- 

 duces a similar characteristic formation of genimaB when culti- 

 vated on solid substrata. The plasma of the filaments collects 

 in certain places in a compact mass, and is then enclosed 

 at both ends by a transverse wall. At the same time the cell 

 swells, the walls grow thicker, and fatty substances are stored 



FIG. 30. Mucor Circinelloides (after VAN TIEGHEM and GAYON) : 1, Mycelium; b, 

 main branch ; c, root-like branches ; r, axillary branches ; 2 4, development of 

 sporangia ; 5, opened sporangia ; 6, spores ; 7, submerged mycelium and budding 

 cells. 



in the interior. The intermediate portions of the hyphse 

 gradually lose their contents. 



Mucor erectus, occurring, for instance, on decaying potatoes, 

 has the same microscopic appearance as Mucor racemosus ; 

 physiologically, however, it differs from this species. 



Mucor circinelloides (Fig. 30) has a very characteristic 

 appearance. The mycelium (1) shows the remarkable branch- 

 ing which occurs in some of the species of Mucor: the 



H 



