PLATE I. 



Zygorhynchcs Moelleri. 



Figures 1-9. (Obj. 7. oc. 4.) 



FiGUKES 1-8. Stages in tlie development of the zygospore showing : — 



Figures 1-3, formation of progametes ; 



Figures 4, 5, formation of gametes ; 



Figure 6, union of gametes ; 



Figure 7, zygote assuming the shape of a zygospore; 



Figure 8, mature zygospore. 

 Figure 9. " Azygospores." 



DiCRAXOPHORA SP. 



Figures 10-13. (Obj. C. oc. 4.) Figure 14. (Obj. 7. oc. 4.) 



Figure 10. Zygophores in contact. 



Figure 11. Formation of a progamete from the larger, and of a gamete from 

 the smaller zygophore. 



Figure 12. Zygote. 



Figure 13. Mature zygospore. 



Figure 14. Protuberance from the hyaline wall corresponding to the " beak " 

 of the mature zygospore. 



Rhizopus nigricans. 

 Figures 15-18. (Obj. C. oc. 4.) 



Figure 15. Three zygospores showing respectively a larger and a smaller 

 gamete in connection with the same hypha. 



Figures 16-18. Stages in hybridization between (+) hyphae of Rhizopus and 

 (— ) hyphae of Absidia. 



MuooR I. 



Figure 19. Gametes showing origin of zygophoric hyphae from adjacent parts 

 of the same mycelial branch. (Obj. C. oc. 2.) 



MucoR MucEDO var. a. 



Figures 20-22. Stages in hybridization between (+) hyphae of M. Mucedo and 

 (— ) hyphae of var. A. (Obj. C. oc. 4.) 



MuCOR III. 



Figure 23. Spores of the (-) strain. (Obj. J. oc. 4.) 



Figure 24. Spores of the (+) strain showing greater dimensions. (Obj. J. 

 oc. 4.) 



