3^0 Desa^iption of Plates. 



Fig. 12. — A tliick-wallcil teleutospore of ihe same. X 200. C. B. V. 



Fig- 13- — Gymnosporangiitin confusum thick-walled teleutospore germi- 

 nating. X 200. C. B. P. 



Fig. 14. — Thin-walled teleutospore of the same, germination rather further 

 advanced. X 200. C. B. P. 



Figs. 15-17. — Three teleutospores of Puccinia amorpha:, showing the 

 gelatinous investment. x 400. C. B. P. 



Plate V. 



Fig. I. — Mycelial hypha of Ustilago scgctum from the base of the stem of 

 Aveiia elatior. X 500. C. B. P. 



Fig. 2. — Mycelial hypha from the rachis of the same plant. x 500. 

 C. B. P. 



Fig. 3. — Mycelial hypha of U. lougissima, the extremity of which has 

 become gelatinized. X 500. C. B. P. 



Fig. 4. — Two gelatinized hyphce of the same, one of which {a) has become 

 nodose, and in it spore-formation has begun (from Glyceria aquatica). X 500. 

 C. B. P. 



Fig. 5. — Gelatinized hypha of U. scgctum from Aveiia elatior. x 500. 

 C. B. P. 



Fig. 6. — Mycelial hypha of Sorosporiitiu sapouarUr, which, after piercing a 

 cell-wall, has become suddenly changed into a spore-forming hypha. X 600. 

 Von Waldheim. 



Fig. 7. — Gelatinized hypha of U. mayd/'s, showing the contents breaking up 

 for spore-formation, x 900. Von Waldheim. 



Fig. 8. — A number of coalesced gelatinized hyphre of U. violacca in which 

 spore-formation is taking place, and the contour of the spores is distinctly 

 observable, x 900. Von Waldheim. 



Fig- 9- — A gelatinized hypha of S. saponaricp, which is coiled upon itself 

 preparatory to the formation of a spore-ball. X 500. Von Waldheim. 



Fig. 10. — A young spore-ball of S. saponarur, with the commencement of 

 four spores seen in section, surrounded by the coalesced gelatinized hyphre. 

 Treated with iodine. X 500. Von Waldheim. 



Fig. II. — A larger spore-ball seen before the coalescence of the hypha?. 

 X 300. Von Waldheim. 



Fig. 12. — Two spores from the interior of a spore-ball still attached to their 

 spore-forming hypha. X 800. Von Waldheim. 



Fig. 13. — The terminal branches of a spore-forming hypha of Urocystis 

 r<7/ir/^?W becoming curved inwards, x 1000? Winter. 



Fig. 14. — The same more advanced ; the external branches from which the 

 pseudospores are developed are embracing the young spore-ball. X 1000? 

 Winter. 



Fig. 15. — Another view of the same, x 1000? Winter. 



Plate VI. 



Fig. I. — Two mycelial hyphie of Tiibcrcinia tricntalis with botryform 

 haustoria. X 520. Woronin, 



Fig. 2. — The primary mycelium of Urocyslis occnlla growing across the 



