15 



pointed and regular in shape when Just mature (Plate I, Figs. 3, 

 8, 9) but when they are old they become wider, misshapen, the 

 beak disappears, and the cells become constricted (Plate II, Fig. 

 11). The normal spores are dark in color and have from four to 

 eight transverse septae. In the young or just mature spores 

 there are few longitudinal septae, but when they become old and 

 constricted thereare many. The spores are borne in great num- 

 bers and are almost without exception in chains, the number in 

 a chain averaging about twelve. From one or more of these 

 spores a side chain may be produced, having as many more (Plate 

 I, Fig. 8). On synthetic media containing no glucose, the chains 

 are shorter and the spores smaller. 



p n i d i p_h o_ res 



The conidiophores vary in length from 100 microns or 

 more to less than 10. They are invariably dark colored and in 

 most cases the cell next the first spore is enlarged slightly, 

 (Plate I, Fig. 8). The width is about the same as that of the 

 mycelium. The septations are often more numerous than in the 

 mycelium. 



My eel ium 



The mycelium is dark colored when well developed, but 

 light when young. It varies from 3 to 9 microns in width. When 

 the mycelium branches a new cell is formed at one side, making 

 almost a right angle, (Plate I, Fig. 14). The aerial mycelium 

 is light colored, much finer, the septations are further apart, 

 and little nodules often appear either at the ends or at the 



