496 LIFE-HISTORIES 
upon the surface of some nutrient medium germinates by 
sending out one or more projections (Figs. 325, 3), and these 
finding abundant food available elongate and branch indef- 
1 
whee oh: ar, 
dZ e/a 
Fic. 324.—Pin-mold (Mucor Mucedo, Pin-mold Family, Mucoracee). 
Plant showing the much-branched horizontal mycelium from which 
arise pin-like vertical hyphe (a, b, c, of different ages) that eventually 
develop dust-spore-cases at the tip. Somewhat magnified. (Zopf.) 
Fig. 325.—Pin-mold. 1, dust-spore-case, viewed as if cut vertically, 
showing the tip of the vertical hypha (c) projecting into the spore-case; 
the spore-case wall (m); and the numerous dust-spores (sp), 225. 
2, same from which the dust-spores have been shed. 3, germinating 
dust-spore, 29°. (Brefeld.) 
initely so long as the conditions are favorable. Soon there 
may be as complex a system of branches as that in Fig. 324. 
A fungus thread is termed a hypha.1 The mass of hyphe 
forming the vegetative part of a fungal thallus constitutes 
1 Hy’pha < Gr. hyphe, a web. 
