48 FUNGI 



enlarges to form the globular sporangium. As the sporan- 

 gium continues to enlarge, protoplasm and numerous nuclei 

 flow into and fill it. Finally this enlarged portion becomes 



FIG. l7.Rhizopus nigricans. Four figures showing the asexual germi- 

 nating spore and the mycelium with aerial and subterranean hyphse develop- 

 ing from the spare. The lower figure shows the sexual spore or zygospore 

 germinating and growing at once into an aerial hypha. 



