[VoL. 3 
78 ANNALS OF THE MISSOURI BOTANICAL GARDEN 
Mechanical or chemical injury to the stem of the host 
caused wilting, but neither yellowing nor dropping of the 
leaves such as is found in diseased seedlings. 
The characteristic symptoms are dependent on a tempera- 
ture of about 17-29°С, or above for their occurrence. Lower 
temperatures (12-16°C.) under controlled conditions pre- 
vented the occurrence of the trouble in the greenhouse. 
Observations made in the field during the summers of 1912, 
1913, and 1914 bore out this relation between the occurrence 
of the disease and high temperature. 
In conclusion, the writer wishes to express to Dr. L. R. 
Jones, at whose suggestion this investigation was undertaken, 
and to Dr. B. M. Duggar, under whom it was completed, his 
sincere appreciation of the many valuable suggestions and 
helpful criticisms given during the progress of this work. 
He is further indebted to the support of the Wisconsin Ex- 
periment Station for the opportunity of conducting the initial 
stages of the work and to the Missouri Botanical Garden for 
the completion of the work upon the problem. 
Graduate Laboratory, Missouri Botanical Garden. 
LITERATURE CITED 
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NU 
Atkinson, с ch (79 ix Damping off. Cornell Univ. Agr. Exp. Sta., Bul. 94:233- 
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— de A id Untersuchungen aus dem Gesamtgebiete der Mykologie 11:27- 
De re y Hedwigia 19: p. 191. 1880. 
Duggar, B. M. ('09). The тр ur conditions of growth ыт. Lg eme 
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a z Y ыс och Effect of temperature on Glomerella. (Science N. 8. 
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