o 



1 8 Description of Plates. 



Fig. 2. — .'Ecidiuin grossii/an'ir at maturity, after rupture of the epidermis 

 and pseudoperidial cell-layer. X 150. De Bary. 



Fig. 3. — Four secidiospores of Puccinia poarum {Vadium tussilaginis). 

 X 475. C. B. P. 



Fig. 4. — One of the same beginning to germinate and showing its germ- 

 pores, five of which are visible, the sixth being on the opposite side of the 

 spore. X 475. C. B. P. 



Fig. 5 — /Ecidiospore of Phragmidinm nibi in the same condition, and 

 showing five germ-pores. X 475. C. B. P. 



Fig. 6. — yEcidiospore oi Puccinia poarum twelve hours after germination, 

 showing the circumnutation of the germ-tube, and the migration of the endo- 

 chrome to its growing end. X 475. C. B. P. 



Fig. 7. — /Ecidiospore of Gymnosporangium clavariirfornie {Rtestelia lacerata), 

 with six germ-pores, from one of which a comparatively short germ-tube has 

 been protruded, which has become branched and full of endochrome from the 

 spore, at its peripheral extremity, x 475. C. B. P. 



Fig. 8. — A basipetal series of eecidiospores of CJirysoniyxa rJiododcudri 

 showing the alternate abortive cells. X 600. De Bary. 



Fig. 9. — ^cidiospore-chain of RcesteUa caiiccUata, showing the undeveloped 

 mother-cells between the spores. X 300. De Bary. 



Fig. 10. — yEcidiospores of Puccinia poarum (yEcidiuvi tussilagiiiis) ger- 

 minating upon the cuticle q{ Poa trivialis, and entering the stomata. X 475. 

 C. B. P. 



Fig. II. — Part of a leaf of Vinca major, with the spermogonia and secidia 

 of Puccinia vincix. X 2. C. B. P. 



Fig. 12. — Section of the same leaf, showing two of the pulvinate secidia. 

 X 10. C. B. P. 



Fig. 13. — Section of a small recidium. X 475. C. B. P. 



Fig. 14. — Two cccidiospores germinating. X 500. C. B. P. 



Plate III. 



Fig. I. — Sorus of the uredospores of Mclampsora farinosa, showing the 

 paraphyses. X 200. De Bary. 



Figs. 2-4. — Uredospores of the same in different stages of development. 

 X 300. De Bary. 



Fig. 5. — Uredospores and mycelium of Puccinia suavccdcjis treated witli 

 caustic potash, showing the development of the spores. X 300. De Bary. 



Figs. 6-8. — Development of the teleutospores of Uromyccs falhc. X 300. 

 De Bary. 



Fig. 9. — Uredospore of Puccinia graininis. X 475. C. B. P. 



Fig. 10. — Two uredospores of the same in the initial stage of germination, 

 showing two germ-pores, x 475. C. B. P. 



Fig. II. — Uredospore of the same after five hours and forty minutes' 

 immersion in water; it has emitted a germ-tube from each germ-pore. X 475. 

 C. B. P. 



Fig. 12. — The same after twenty-three hours. One germ-tube has ceased 

 to grow and is, like the spore, empty ; the other, which is empty and septate 



