IOWA ACADEMY OF SCIENCE 
45 
EXPLANATION OF PLATES. 
PLATE I. 
Fig. 1 . Phyllactinia corylea tomentosa. a and b, two appendages; c, an 
appendage of the typical P. corylea from same leaf as a and b. (Author’s 
illustration.) 
Fig. 2. Hyphae and conidia of Erysiphe cichoracearum, from leaf of Hydro- 
phyllum virginicum. (Drawn by Miss King.) 
Fig. 3. A fruit of Ampelomyces quisqualis. a. A mycelium of Erysiphe 
with the fruit of Ampelomyces; b, arising out of it; c, spores escaping from 
the ruptured end of fruit. (Author’s illustration.) 
PLATE II. 
(Drawn by Miss King.) 
(See page 48.) 
Fig. 1. A perithecium of Uncinula circinata from a leaf of Acer sacchar- 
inum showing very numerous appendages uniformly coiled at apex. 
Fig. 2. Perithecia of Sphaerotheca uiors-uvae from the cultivated goose- 
berry, showing few or obsolete appendages and the persistent mycelium in 
which they are immersed. 
PLATE III. 
(See page 46.) 
Showing Variations in Erysiphe polygoni. (Drawn by Miss King.) 
Fig. 1. From a leaf of Clematis virginiana, showing few, but long flexuose 
appendages. 
Fig. 2. From a leaf of Astragalus carolinianus, showing more numerous 
but short appendages, b. Tips of appendages. 
