428 BULLETIN OF THE BUSSEY INSTITUTION. 
PERONOSPORA PARASITICA, Pers. De Bary, l. c. No. 7. My- 
celium large. Haustoria very large, branching. Conidial-bearing hy- 
phz repeatedly dichotomous. Ultimate divisions slender, divaricate. 
Conidia ellipsoid obtuse. Germinal tube given off from any part of 
conidia. Odspores round ; epispore, slightly yellow, smooth, or slightly 
rugose. | 
Cabbage leaves. Society Hill, N. C. March, 1849. Curtis, No. 
2259. On Cardamine rhomboidea, D. C. Buffalo N. Y., Clinton in 
26th Report of N. Y. State Botanist, by Peck. Leptdiwm Virgini- 
cum, L., Noank, Conn., Aug. 1875. 
PERONOSPORA EFFUSA, GREV., De Bary, l. c. No. 16.— Mycelium 
cylindrical. Haustoria filiform. Conidial-bearing hyphez repeatedly 
dichotomous. Divisions of ultimate dichotomy unequal, flexuous, re- 
curved. Conidia large, ellipsoidal, dirty-violet, colored. Germination 
by a lateral tube. Odspores globular; epispore dark-colored, with 
irregular projections. 
To this species we refer two specimens found among the undeter- 
mined fungi of the Curtis collection, labelled “ Atriplex, Albany.” 
Besides these, we found at Newton, Mass., August, 1874, a Perono- 
spora on the under-surface of leaves of Plantago mar, with both 
odspores and conidia, which is apparently the same species as that on 
the Atriplex, and which agrees perfectly with European specimens of 
P. effusa, Grevy., although that occurs on Chenopodiacee and Polygo- 
nacee. JP. alta, Fuckel, of which the odspores are unknown, occurs on 
the leaves of Plantago major, and the description answers very well 
to our plant. We must confess, however, that the description of that 
species also answers remarkably well for our European specimens of 
P. effusa on Chenopodium ; and we must consider that our plant whose 
conidia germinate by means of a lateral filament is P. effusa, rather 
than the somewhat doubtful P. alta. | 
It is possible that the ‘onion-disease so destructive in Connecticut is 
caused by Peronospora Schleideniana, Unger, which is injurious to 
onions in Europe. We have not, however, been able to examine 
specimens of the Connecticut disease ; nor do we know of any scien- 
tific investigation of the subject. 
