ANATOMY OF FUNGI 25 



ANATOMY OF FUNGI 



The spore on germination usually gives origin to a 

 cylindrical outgrowth or germ-tube, which by continued 

 apical growth and the formation of lateral branches pro- 

 duces a more complicated structure called a hypha. The 

 hyphae collectively constituting the vegetative portion of the 

 fungus, so long as they remain free from each other, that 

 is, not compacted together to form solid masses or cord- 

 like bodies, constitute the mycelium, popularly known as 

 spawn. In some fungi belonging to the Phycomycetes the 

 hyphal system consists of one continuous tube, or becomes 

 cut up into cells by the formation of cross-walls or septa 

 previous to the formation of fruit. In the majority of 

 fungi, however, the hypha develops as a string of cells 

 owing to the continuous formation of septa just behind 

 the apex. In some instances intercalary septa are formed 

 at a later period in portions of hyphae remote from the 

 growing point. 



A peculiar feature common in most groups of fungi, 

 excepting the Phycomycetes, is the coalescence at various 

 points of independent hyphae. When spores germinate in 

 a hanging drop, the different germ-tubes that come in 

 contact fuse together, the walls of both hyphae disappear 

 at the point of contact, and the cavities of the two tubes 

 become continuous. In some instances an irregular net- 

 work of hyphae, resulting from numerous fusions, is 

 formed. In other instances where two hyphae run parallel 

 to each other, but at some distance apart, a lateral branch 

 from one hypha grows out until its point comes in contact 

 with the other hypha, when fusion takes place, forming an 



