illustrations 
PLATES 
A New Bacterial Citrus Disease 
Page 
Plate A. I, 2.—Orange twigs, showing brown blister-like scabs of Citrus blast, 
formed in summer over affected parts. 3.—Natural infection upon young 
leaves of a navel-orange tree. 8 
Plate I. A.—Flagella of Bacterium citrarefaciens from 24-hour-old agar slant. 
B.—Filamentous bodies showing thickened areas of denser protoplasm 
from saccharose bouillon cultures of Bad. citrarefaciens. C.—Cross section 
of a navel-orange leaf affected with Citrus blast. 8 
Plate 2.—Tree affected with Citrus blast, showing bared twigs and wilted 
leaves.. 8 
Xylaria Rootrot of Apple 
Plate 3. A.—Stromatic arms formed in cultures on steamed com meal; re¬ 
sembling those of certain species of Xylaria. B.—A few stromatic arms 
from the same culture...... 276 
Comparison of the Hourly Evaporation Rate of Atmometers and Free 
Water Surfaces with the Transpiration Rate of Medicago sativa 
Plate 4.—Types of porus-cup atmometers used in evaporation measurements: 
A.—White cylinder. B.—White sphere. C.—White Bellani plate. D.— 
Brown cylinder.. 292 
Plate 5.—Special filter-paper evaporimeter used by the writers, equipped 
with Mariotte control (a) for the purpose of maintaining a constant water 
level in the filter-paper container ( b) .... 292 
Plate 6. A.—Shallow, blackened evaporation tank mounted on automatic 
balance. B.—Deep evaporation tank as used at Akron, Colo. 292 
The Pink Bollworm, Pectinophora gossypiella 
PLATE 7. A. — Pectinophora gossypiella: Adult. B.- — Pyroderces rileyi: Adult.. 370 
Plate 8. A.— Pectinophora gossypiella: Right hindleg. B.— Pectinophora 
gossypiella: Genitalia of male. C.— Pectinophora gossypiella: Genitalia of 
female. D. — Pyroderces rileyi: Right hindleg. E.— Pyroderces rileyi: 
Genitalia of male.•... 370 
Plate 9. A.— Pectinophora gossypiella: Larval head from underside. B.— 
Pectinophora gossypiella: Seta arrangement of epicraneum in figure A. 
C.— Pectinophora gossypiella: Labium and maxillae. 370 
PLATE IO. A.— Pyroderces rileyi: Epipharynx of larva. B.— Pyroderces rileyi: 
Labrum of larva. C.— Pyroderces rileyi: Underside of third abdominal 
segment of larva. D.— Pectinophora gossypiella: Right mandible of larva 
from underside. E.— Pectinophora gossypiella: Left mandible from under¬ 
side. F.— Pectinophora gossypiella: Right mandible from underside. G.— 
Pectinophora gossypiella: Left mandible from upper side. H.— Pectinophora 
gossypiella: Left antenna of larva from underside. I.— Pectinophora gossy¬ 
piella: Epipharynx of larva. J.— Pedinophora gossypiella: Labrum of larva. 
K. —Pectinophora gossypiella: Underside of third abdominal segment of 
larva. 370 
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