2i6 Explanation of Plates. 



PLATE XXVII. 



(All Figures x 500 unless otherwise stated.) 



USTILAGO. . 



Fig. 



12. Strongly developed branched germinal tube from spore of U. hordei. 



13. Spores of U. nuda. 



14. 15. Germinating spores of U. nuda. 



16. Stronglj' developed germinal tube from spore of U. nuda. 



17. Germinating spores of XJ. nuda. showing different stages of development of the 



germinal tube (after Brefeld) . . . . . . . . . . x 350 



15. Spore germination of U. hordei in a nutritive solution (after Brefeld) . . x 350 



