320 Description of Plates. 
Fig. 12.—Promycelial spore emitting a germ-tube. x 500. C. B. P. 
Fig. 13.—Promycelial spore producing a secondary promycelial spore in 
water. xX 500, C. B. P. 
Fig. 14.—Ustilago longissima. Teleutospore just beginning to germinate. 
x 500. C. B. P. 
Fig. 15.—The same a little later, showing the septation of the promycelium 
and the separation of the promycelial spore. x 500. C. B. P. 
Fig. 16.—The same after two promycelial spores have been thrown off, and 
a third is almost ready to be so. xX 500. C. B. P. 
Fig. 17.—Ustilago kiihneana. Teleutospore germinated, showing the promy- 
celial spores in whorls on the promycelium. x 350. Brefeld. 
Fig. 18.—Ust¢lago scabiose on Scabiosa arvensis, twelve hours after germi- 
nation in water (September 1, 1884). x 500. C. B. P. 
Fig. 19.—Ustilago major on Silene otttes, gathered near Paris, October, 
1887 ; germinated at the beginning of November. Twenty hours in water, 
showing the promycelium, which has nearly attained its full development. 
x 500. C. B. P. 
Fig. 20.—The same at twenty-four hours, having become septate. X 500. 
Cc. B. P. 
Fig. 21.—Teleutospore with promycelium still attached (thirty-six hours), 
which has produced a promycelial spore at its apex. This is quite an excep- 
tional circumstance with this species. x 500. C. B. P. 
Fig. 22.—Three promycelia which have fallen off the teleutospores (twenty 
four hours). xX 500. C. B. P. 
Figs. 23-25.—Three promycelia which have produced promycelial spores 
both terminally and laterally, after having fallen away from the teleutospores 
(forty-eight hours). x 500. C. B. P. 
Fig. 26, 27.—Spore-balls of Urocystis primulicola, germinating (August 31, 
1884) after forty-eight hoursin water. They have emitted promycelia, probably 
from the central spores—but on this point I was unable to satisfy myself, which 
have given origin to promycelial spores, one of which (Fig. 27) has produced a 
secondary promycelial spore. x 475. C. B. P. 
Fig. 28.—Two promycelial spores conjugating, after fifty hours in water. 
x 500. C. B. P. 
Fig. 29.—Two promycelial spores which have become vacuolate and 
septate, after two hundred and sixty-four hours in water. x 500. C. B. P. 
Fig. 30.—Promycelial’ spore emitting a germ-tube, after one hundred and 
sixty-eight hours in water. x 500. C. B, P. 
Fig. 31.—Uvocystis anemones. Teleutospore germinating in water, Novem- 
ber 25, 1884. x 475. C.B.P. 
Fig. 32,—Two promycelial spores of the same conjugating. Xx 500. 
C. B. P. 
Fig. 33.—Two promycelial spores of the same which have become vacuo- 
late and septate. x 500. C. B. P. 
Fig. 34.—Spore-ball of Urocystis fischeri, one teleutospore of which has 
germinated. x 500. C.B. P. 
Fig. 35.—Three promycelial spores of the same. x 500. C. BP. 
