10 BACTERIOLOGY 



A tubular bud pushes out from the enveloping mem- 

 brane of the spore, lengthens by growing at the end, and 

 quickly forms a very freely-branching network of fibres, 



Mycelium 



FIG. 4. PENICILIUM G-LAUCUM. Magnified 400 times. (After Baumgarten.) 



spoken of as mycelium, and possessing special seed-bearing 

 organs called hyphce or thallus, from which the moulds 

 derive the name of Hyphomycetce. According to the form 

 of the seed-organ they are divided into mucorinece, aspcr- 

 giUinece, penicilliaccce, and oidiacccc. 



Conidia 

 Hyphe 



Mycelium 



FIG. 5. OJDIUM LACTIS. (After Baumgarteu.) 



In the mucorinece, or headed moulds, the ends of the 

 hyphse swell into knobs (columella), around which a seed- 

 capsule, or sporangium, forms. In this the spores develop 

 in such a way as to burst the enveloping epicarp membrane 

 when fully ripe (fig. 2). 



The aspergillinece (knob-moulds) have the knobbed ends 



