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A TEXTBOOK OF THEORETICAL BOTANY 



Fig. 233. — Miicor sp. growing on a piece of damp bread 

 showing black sporangia. 



Fig. 234. — Mucor mucedo. Two stages in the dehiscence of 



sporangium. 



Asexual Reproduction 



Within a few days of the appearance of the myceHum asexual reproduction 

 begins. Vertical hyphae (sporangiophores) grow out from the mycelium, 

 which are destined to produce terminal sporangia. The sporangium is 

 formed by the enlargement of the apex of the hypha into a spherical vesicle 

 containing many nuclei. The protoplasm of the sporangium is divided by 

 cleavage planes into uninucleate masses, from each of which an ellipsoidal 

 spore is formed. By a similar cleavage plane a dome-shaped septum is 

 formed in the basal part of the sporangium, called the columella, which 



