Description of Plates. 321 
interspace between the inner surface of the primary embryonic sheath and 
the outer surface of the embryo of a rye plant. x 375. Wolff. 
Fig. 3.—Promycelial spore of 77/etia /evis entering the primary sheath 
of a wheat plant and invaginating a sheath of cellulose. x 600. Wolff. 
Fig. 4.—Spore-forming hypha of 77Uetia tritict from wheat, showing the 
budding of the spores; from an ovary 1 mm, long. x 900. Von Waldheim. 
Fig. 5.—The extremity of a spore-forming hypha of the same, showing 
two spores in different degrees of development. x 500. Von Waldheim. 
Fig. 6.—Transparent single-contoured spore of the same, with shrivelled 
remains of the spore-forming hypha. x 500. Von Waldheim. 
Fig. 7.—Teleutospore of 7. ¢ritic’ germinating after forty-eight hours in 
water. x 500. C. B. P. 
Fig. 8.—The same more advanced, showing the H-shaped spores (primary 
promycelial spores conjugated), two of which have already fallen away from 
the promycelium. x 300. C. B. P. 
Figs. 9, 10.—Primary promycelial spores conjugated, empty, and septate, 
each pair of which has produced a secondary promycelial spore. x ‘300. C. 
B. P. 
Fig. 11.—Two secondary promycelial spores conjugating. x 350. C. 
B. P. 
Fig. 12.—The samea little later. A germ-tube has been given off from one 
of the spores. x 350. C. B, P. 
Fig. 13.—A single unconjugated secondary promycelial spore giving off a 
germ-tube. x 350. C. B. P. 
Fig. 14.——Mycelium from a single primary promycelial spore in nahrlosung 
producing conidia. x 100. Reduced from Brefeld. 
Fig. 15.—A small portion of the same more highly magnified. x 357. 
After Brefeld. 
Puate VII. 
Fig. 1.—Ustilago segetum. Teleutospore germinating in water after sixteen 
and ahalfhours. x 500. C. B. P. 
Fig. 2,—The same, with a secondary promycelial spore produced from a 
primary while still attached to the promycelium. x 500. C. B. P. 
Fig. 3.—A promycelium of the same forming a buckle joint. x 500. 
C. B. P. 
Fig. 4.—A promycelium of the same forming a bow joint. x 500. After 
Brefeld. 
Fig. 5.—Two promycelia conjugating. x 500. C. B. P. 
Fig. 6.—A promycelium growing out into a germ-tube. x 500, After 
Wolff. 
Fig. 7.—Two promycelia given off from one teleutospore. x 500. C.B. P. 
Fig. 8.—Yeast-spores produced from a promycelium in nahrlosung (three 
days). x 500. C. BP. 
Fig. 9.—A promycelium with a buckle joint and secondary promycelial 
spores in exhausted nahrldsung (twelve days). x 500. C. B. P. 
Fig. 10.—A_ yeast-spore colony, produced from a single teleutospore. 
x 500. Brefeld. 
Fig. 11.—Promycelial spores conjugating. x 500. C. B. P. 
Y 
