19 14] FROMME—AECIDIUM CUP 35 



Figs. 4 and 5. — Two early stages of cell fusions. 



Fig. 6. — A completed cell fusion. 



Fig. 7. — A tricellular fusion. 



Fig. 8. — A two-legged basal cell and above it an aecidiospore initial cell; 

 4 nuclei are found in both cells as the result of the preceding conjugate divisions; 

 X 900. 



Fig. 9. — A trinucleated basal cell and aecidiospore initial cell. 



Fig. 10. — Early stage of conjugate mitosis in an aecidiospore initial cell. 



Fig. 11. — Anaphase of conjugate mitosis in a fusion cell. 



Fig. 12. — Simultaneous division of three nuclei in a fusion cell. 



Fig. 13. — A later stage than the preceding; the elongated spindles lie 

 parallel with each other and the long axis of the fusion cell. 



Fig. 14. — A chain of quadrinucleated aecidiospores and intercalary cells; 

 X570. 



Fig. 15. — Three peridiai cells from the central region of the peridium; X 570. 



Uromyces Caladii 



Figs. 16 and 17. — Two cases of completed cell fusions. 

 Fig. 18. — A tricellular fusion. 

 Fig. 19.— A two-legged basal cell. 



Puccinia Violae 



Fig. 20. — A very early stage of cell fusion in which the fusion pore is still 

 very small. 



Fig. 21. — A completed cell fusion. 

 Fig. 22. — A two-legged fusion cell. 



Puccinia Hydrocotyles 

 Fig. 23. — Three cases of cell fusion within a small area; the borders of two 



figu 



Puccinia Eatoniae 



Fig. 24. — Fusion between two cells in horizontal lying hyphae near the base 

 of the sorus; the base of a two-legged fusion cell lies just above the fusing 

 gametes. 



Fig. 25. — A two-legged fusion cell that has bent up at a sharp angle and 

 elongated in the direction of the epidermis. 



Puccinia angustata 

 Figs. 26 and 27. — Two-legged basal cells. 



