Reed—Infection Experiments. 
lod 
Salmon (10) made several infection experiments with the mil¬ 
dew of the grasses, especially of the Brome grasses. He finds that, 
instead of there being one special form for all the Brome grasses, 
<as stated by Marchal, there are at least four and probably five 
distinct biologic forms on the Bromes. 
Salmon also obtained the following results with the mildew 
from other plants. These results in general confirm the work 
of Marchal. 
1. Conidia of Erysiphe graminis DC. from wheat will infect 
wheat and Triticum Spelia but not oats, barley, rye, nor Ag- 
ropyron repens. 
Conidia from oats will infect oats, Avena brevis, A. nuda, 
A. sterilis, A. strigosa, and A. orientalis, but not wheat, barley, 
rye, Festuca elatior, F. heterophylla, Poa annua, Dactylis glom- 
erata, Arrhenatherium elatius, Trisetum pratense, Phleum pra- 
tcnse, Alopecurus pralcnsis, nor Lolium Ilalicum. 
Conidia from Avena nuda will infect oats, A. brevis, and A. 
nuda. 
2. Conidia of Erysiphe polygoni DC. from Trifolium pra¬ 
tense will infect T. pratense, but not T. agrarium, T. repens, T. 
medium, T. montanum, T. incarnatum, T. hybridum, T. fill- 
forme, Lotus corniculatus, Melilotus arvensis, Medicago sativa, 
Lupinus luteus, nor Pisum sativum. 
Conidia from Pisum sativum will infect P. sativum but not 
Lupinus luteus, Colutca arborescens, Onobrychis saliva, nor 
Trifolium pratense. 
It is interesting to note that the mildew on the oats was able 
to infect a number of other species of grasses belonging to the 
same genus whereas the mildew on Trifolium pratense was un¬ 
able to pass over to any other species of the same genus. 
Salmon (12) studied still further the infection power of the 
conidia of several species of mildews. His results are as follows: 
1. Conidia of Erysiphe graminis from Avena sterilis will in¬ 
fect A. sterilis, A. sativa, A. pratensis, but not Arrhenatherum 
avenaceum, Lolium temulentum, Festuca elatior, Bromus unio- 
loides, nor B. stei'ilis. 
Conidia from Agropyron repens will infect A. repens, A. 
tenerum, A. caninum, but not A. glaucum nor A. acutum. 
