ASEXUAL REPRODUCTION 



119 



are the spores. In the third type, illustrated by Ciimiinghainella 

 echifiulata and C. berthoUetiae [Moreau (1913)1, the tip of the 

 sporangiophore enlarges into a capitate structure. Short pro- 

 tuberances (sterigmata) then appear over the surface of this 



Fig. 36. Mucor vnicedo. A. Sporangium in section with oblong columella. 

 B, C, and D. Stages in formation of zygote. In B, the progametes have 

 come into contact; in C, the gametes have been delimited and are sup- 

 ported by suspensors; in D, the rough, thick-walled zygote has developed. 

 E. On germination of zygote a tube is formed that is surmounted by a 



germ sporangium. 



Structure, and small globular enlargements develop at the tips of 

 the protuberances. Each enlargement receives a complement of 

 protoplasm and 3 to 8 nuclei and is eventually ab jointed to be- 

 come the spore. 



Various modifications of these three types of spore formation 

 are exhibited by certain other of the Mucorales. In Syncephalis 

 and Syncephalastrum long tubes (sporangia) develop at the tips 

 of sterigmata that project in all directions from a globular head- 



