DAMPING-OFF IN FOREST NURSERIES. 35 
cated as -more strongly parasitic than F. solani, but in a single test 
only and with a culture of doubtful purity. Fusarium acuminatum 
E. and E. gave no evidence of parasitism. These results agreed with 
those of Spaulding (137) in indicating that the ability to attack 
seedling conifers is not limited to a single species of Fusarium and 
that F. moniliforme is one of the more virulent. The statement by 
Hartig (61, p. 147-150) that a Fusariumlike fungus was able to cor- 
rode the young epidermis of pine seedlings has already been men- 
tioned. 
PYTHIUM DEBARYANUM. 
Pythium deharyanum Hesse (Artotrogus deharyanum Atkinson, 
Lucidium pythioides Lohde) has been known since 1874 (74, 86) as 
a common cause of damping-off of various angiosperms. The first 
known observation was made by De Bary about 1864 (74). Despite 
the large number of hosts on which it has been listed, its parasitism 
has been definitely established on few. Peters (100) has successfully 
inoculated sugar beets with pure cultures ; at least part of his strains, 
including presumably part or all of those he used in inoculation tests, 
were obtained from single spores. Edson (38) working with the 
same host, reisolated the fungus from inoculated seedlings, and made 
reinoculations with it. Both find it able to cause root sickness of 
plants not attacked early enough to be killed outright. Johnson 
(82) and Knechtel (85) have caused damping-off of tobacco seed- 
lings with it, and the former reported it also able to persist in the 
cortex and kill the lower leaves of tobacco plants which survived 
attack. The fungus has long been reputed parasitic on potato tubers 
and has now been found by Hawkins (70) to be the chief cause of 
the rot known as "leak" in California. Peters (99) made success- 
ful inoculations with pure cultures on cuttings of Pelargonium. 
Most of the reports of parasitism, however, have been based on 
microscopic examination or more or less crude inoculation experi- 
ments. Noteworthy among the latter are those reported by Hesse 
(74) on Camelina sativa in the original description of the fungus. 
These were made before pure-culture technique had come into use 
with fungi, but were so thoroughly checked by microscopic obser- 
vations at every step- in the process that they must be admitted as 
very good evidence of the parasitism of the fungus. A number of 
reported angiospermous hosts are listed by Butler (23), Voglino 
(143), and Johnson (82, p. 34, footnote, and p. 35). Reinking (107) 
recently reported Canica papaya as attacked. A host which the 
writer has not found in the literature is rice, found by Dr. Haven 
Metcalf seriously attacked in the seedling stage in a field in South 
Carolina. A second apparently new host for the fungus is fenu- 
greek (Trigonella foenum-graecum). The writer found oospores 
typical of Pythium deharyanum in the tissues of damped-off seed- 
