THALLOPHYTES: FUNGI 



53 



Erect sporophores arise from it in abundance, and at 

 the top of each sporophore a globular sporangium is formed, 

 within which are numerous small asexual spores (Figs. 35, 



FIG. 34. Diagram showing mycelium and sporophores of a common Mucor. 

 CALDWELL. 



36). The sporangium wall bursts (Fig. 37), the light spores 

 are scattered by the wind, and, falling upon a suitable sub- 

 stratum, germinate and 

 form new mycelia. It is 

 evident that these asex- 

 ual spores are not zoo- 

 spores, for there is no 

 water medium and swim- 

 ming is impossible. This 

 method of transfer being 

 impossible, the spores are 

 scattered by currents of 

 air, and must be corre- 

 spondingly light and pow- 

 dery. They are usually 

 spoken of simply as 

 " spores," without any 

 prefix. 



22 



FIG. 35. Forming sporangia of Mucor, show- 

 ing the swollen tip of the sporophore (A), 

 and a later stage (S), in which a wall is 

 formed separating the sporangium from 

 the rest of the body. CALDWELL. 



