DORAN: ON THE GERMINATION OF FUNGOUS SPORES 331 
the surface. The conidia of Venturia inaequalis germinated 
only when they were on or near the surface of the water. Telio- 
spores of Puccinia Malvacearum did not produce sporidia when 
deeply submerged in the drop. But when distilled water was 
used, which had previously been aerated, equally good germina- 
tion was secured whether or not the spores were submerged 
in the drops. 
DeBary (47) described the behavior of spores in water be- 
tween a cover glass and a glass slide. In this case, the spores 
TABLE IV 
Time period necessary for the germination of representative 
fungous spores — optimum conditions 
Fungus and spores No. of hours|Spores germinating (relative numbers) 
Cronartium ribicola, IO. °o 
Aeciospores 12 100 
Cronartium ribicola, 5-5 100 
Urediniospores 
Gymnosporangium clavipes ,| 4.0 100 
Aeciospores : 
Puccinia Malvacearum, 2.0 |Producing basidia too. Producing 
Teliospores basidiospores o 
3.0  |Producing basidiospores 100 
Sclerotinia fructigena, 5.0 100 
Conidia 
Venturia inaequalis, 16.0 25 
Conidia 27.0 100 
near the periphery of the cover glass germinate better than those 
near the center due‘to the relative amounts of air available. 
Duggar (3) found that a reduced oxygen supply retards spore 
germination. Blackman (48) noticed that if the germ tube of 
Phragmidium violaceum does not grow through the water and 
so reach the air it develops abnormally. Weimer (9) observed 
that when the teliospores of Gymnosporangium Juniperi- 
virginianae are covered with water they produce only long tubes 
instead of the normal promycelia and basidiospores. Melhus 
