CH. VIIl] 



MUCOR. 



113 



heads (in which the spores are produced) are called 

 sporangia. The sporangium is originally a swelling at 



FIG. 49. 

 MUCOR. 



A. Diagrammatic sketch showing the mycelium and the sporangia 

 borne on vertical hyphae. 



B. Various stages in the germination of a spore ; /, mycelium with 

 vacuoles. 



C. A ripe sporangium containing spores, and covered with a coating of 

 calcium oxalate crystals ; ID, the collar. 



D. A burst sporangium; col, the columella to which two spores adhere ; 

 iv, the collar. 



the top of a hypha cut off from the rest of the mycelium 

 by a cell-wall. The contents of this terminal cell become 

 separated into a large number of small masses of proto- 

 plasm, and these when they have clothed themselves with 

 cell- walls are the spores. But before this a change takes 

 place in the cross- wall at the base of the sporangium : 

 D. E. B. 8 



