THE FUNGI : ARCHIMYCETES AND PHYCOMYCETES 245 



Zygospore 



Suspensor 



Fig. 237. — Rhizopiis nigricans. Isolated 

 zygospore with attached suspensors. 



Fig. 238. — Mucor hiemalis. Detached zygospores with 

 spiny exospores. 



Various interpretations of the nuclear behaviour inside the zygospore 

 have been suggested, but owing to the very small size of the nuclei there 

 is no agreement between the views expressed. It may be that there is 

 general pairing of the nuclei, so that a number of diploid nuclei are produced, 

 or, as seems more likely, that only one nucleus from each gametangium 

 actually fuses. 



