172 



Mycologia 



Fig. 17. Tangential section of a sporangium, the irregular blocks of pro- 

 toplasm are being cut up into spores, the nuclei are not we'll shown. 

 Fig. 18. Mature multinucleate spores. 



Mucor mucedo 



Fig. 19. Median vertical section of a sporangium, columella-cleft nearly- 

 complete on one side but in the early stage on the other side. 



Fig. 20. Outline drawing of a section of a sporangium showing cleavage 

 of spore-plasm into relatively large protoplasmic blocks. 



Fig. 21. Section of a sporangium showing spore-plasm cut up into uni- 

 nucleate spore-initials. 



Fig. 22. Outline drawing of a median vertical section of a small sporan- 

 gium showing polyhedral spore initials. 



