DESCRIPTION OF PLATE?. 



Plate I. Frontispiece. A perennial rast. jEcidium tuberculatum E. and K. on Cal- 

 lirrhoe involucrata Gr. 



Plate II. Fig. 1. — Seedling of Euphorbia dentata grown constantly under 1 veil jar 

 from rusted seed. Fig. 2. — Puccinia vexans Farl. on Bouteloua racemose^ both 

 uredosori and ainphisori being shown. (Natural size.) Fig. 3. — The same ure- 

 dosori and amphisori shown in fig. 2 magnified 10 diameters. Fig. 4. — Uredo- 

 spores of Puccinia vexans X 600. Fig. 5. — Amphispores of Puccinia vexans X 600. 

 Fig. 6. — Teleutospore of Puccinia vexans X 600. Fig. 7. — Germinating uredo- 

 spore of Puccinia vexans X 300. Fig. S. — Germinating amphispores of Puccinia 

 vexans X 300. Fig. 9. — Uredosori of Puccinia vexans on young seedling leaf of 

 Bouteloua racemosa produced by artificial infection with uredospores from the 

 same host. (Natural size). 



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