494 BULLETIN OF THE BUSSEY INSTITUTION. 
(raro 3, v. 7) gerentes. Rami primarii plerumque alterni, distantes et 
exacte distichi, omnes pro stipitis altitudine breves; inferiores plerum- 
que trifurcati divisionibus iterum bis trifurcatis v. quandoque bis dicho- 
tomis; ramuli ultimi (quarti) ordinis, eque ac stipitis divisiones apica- 
les, brevissime conico-subulati recti, acuti. Rami primarii superiores 
minores, inferiorum secundariis v. tertiariis conformes. Rami omniam 
ordinum angulis rectis patentes, primarii in uno plano divaricati, 
planum ramificationum secundi ordinis in primario, tertiarorum in 
primario et secundario perpendiculare. (Rarius rami primarii 2 infe- 
riores oppositi sunt, raro ramulis 2 alterius muniti nec trifurcati, raris- 
sime rami primarii irregulariter sparsi nec distichi sunt.) Conidia 
parvula, ovoidea, apice lato rotundata v. subtruncata, papilla destituta, 
membrana circumcirca quali hyalina. Odgonia parva, membrana 
tenui hyalina v. lutescente odsporam foventia subglobosam episporio 
tenui fuscente diaphano levi munitam.” 
Tt is again referred to as a Botrytis by Curtis, in his “ List of Plants 
of North Carolina,” 1867; by Peck, in the “Twenty-third Report of 
the N. Y. State Botanist,” for 1869 (pub. 1873); and by Frost, in 
Tuckerman’s “ Catalogue of Plants within Thirty Miles of Amherst 
College,” 1875, and Berkeley, in “ Grevillea” for March, 1875, 
“Notices of N. A. Fungi,” No. 667, gives the following description : 
“ Peronospora viticola, B. & C. Floccis candidis sursum ramosissi- 
mis apicibus breviter emarginatis furcatisve; sporis ovatis. On the 
under-side of leaves of Vitis @estivalis. Santee River, Ravenel, No. 
1632; New England, Sprague, No. 5764; Missouri, Dr. Engelmann. 
Forming orbicular white spots; flocci articulated, much branched 
above; the apices emarginate, or shortly forked and acute; spores 
ovate. In those varieties where the leaves are woolly beneath, the ~ 
spots are less conspicuous.” 
Although our plant has been considered quite distinct among the 
species of Peronospora, it seems to us that one cannot fail to see a 
decided resemblance to P. nivea, Unger. The conidia differ from 
those of the latter species in being smaller, and in not having an apical 
papilla, but resemble them, and those of P. infestans, in their mode of 
germinating. The conidial-bearing hyphe in P. viticola are taller, 
and comparatively more slender, than in P. nived ; but the peculiar 
tripartite division of the tips, so uniform in P. viticola, is also fre- 
quently found in P. nivea, although in the latter they are much more 
