270 
PLANT STUDIES 
While the ordinary method of reproduction through the 
growing season is by means of these rapidly germinating 
spores, in certain conditions a sexual process is observed, 
by which a heavy-walled sexual spore is formed as a resting 
spore, able to outlive unfavorable conditions. Branches 
arise from the hyphae of the mycelium just as in the forma- 
Fio. 236. Mature sporangium of Mucor, showing 
the wall (A), the numerous spores (C), and 
the coluraella (B) that is, the partition wall 
pushed up into the cavity of the sporangium. 
MOORE. 
FIG. 237. Bursted sporangium of 
Mucor, the ruptured wall not 
being shown, and the loose 
spores adhering to the colu- 
mella. MOORE. 
tion of sporophores (Fig. 238). Two contiguous branches 
come in contact by their tips (Fig. 238, A), the tips are cut 
off from the main ccenocytic body by partition walls (Fig. 
238, 5), the walls in contact disorganize, the contents of 
the two tip cells fuse, and a heavy-walled sexual spore is 
the result (Fig. 238, C). It is evident that the process is 
conjugation, suggesting the Conjugate forms among the 
