214 Explanation of Plates. 



PLATE XXVI. 



[All Figures x 500 unless othenvise stated.) 



USTILAGO. 



Fig. 



1. Spores of U. a venae. 



2. Spore-germination of U. avenue in water (after Brefeld) x 450. The upper row- 



shows the formation of conidia. The lower row is an older stage, where the 

 formation of conidia has ceased, and the spore at the end sliows a " buckle 

 joint," i.e., one segment of the promyceliura becomes connected with another 

 by means of a curved tube. 



3. Spore-germination of U. avenae in nutritive solution, showing the luxuriant formation 



of conidia (after Brefeld) . . . . . . . . . . X 200 



4. C4erminating spore of U. avenae forming a buckle joint. 



5. Germinating spore of U. avenae emitting a long branched septate tube instead of the 



ordinary promycelium. 



6. Germinating conidium of U. avenae. 



7. Spores of U. hordei. 



8. 9. Germinating spores of U. hordei, with conidia. 



10, 11. Spores of U. hordei germinating and forming branching septate elongated tubes. 



