424 



BOTANY OF THE LIVING PLANT 



bears one sporangium on its end, which when ripe consists of a brittle 

 external wall surrounding many spores embedded in a mucilaginous 

 matrix, while centrally is a large columella (Fig. 359, A). It is 

 difficult to see this structure satisfactorily in ripe sporangia mounted 

 in water, owing to the swelling of the mucilaginous matrix, which 



FIG. 359- 



A plant of Mucor, showing the mycelium of branched hyphae (m) and sporangia 

 (g). A is a single sporangium more highly magnified, containing spores. (After 

 Brefeld.) 



bursts the wall and scatters the spores (Fig. 360). Their dissemina- 

 tion is thus through the assistance of water, not in the dry and dusty 

 state common for most Fungi. 



Though this is the case for the typical Mucors, there are many Mucorineous 

 Fungi in which the dissemination of spores is through the air. They are 

 found among those smaller forms which live parasitically on the larger Mucors, 

 and frequently appear upon old cultures of these as flocculent growths attached 

 by suckers to their sporangiophores (Chaetocladium, Piptocephalis). In 



