ZONATION IN ARTIFICIAL CULTURES. 117 
‘EXPLANATION OF PLATES. 
Plate 13.— 1. Penicillium album, grown in the light. 2. Cephalothecium 
roseum from sugar beet roots, grown in light. — Natural size, 
Plate 14.—1. Cephalothecium roseum, from apple, grown in dark- 
ness. 2. Same, grown in light. 
Plate 15.—1. Cephalothecium roseum, from Rosa rugosa fruits, 
grown in darkness. 2. Same, grown in orange light. — Colonies enlarged. 
Plate 16.— 1. Cephalothecium roseum, from Rosa, grown in blue 
light. 2. Same, grown in natural light. — Colonies enlarged. 
