NOTES ON THE ERYSIPHACEAE 183 
his plant: ‘Durch die askenarmeren Perithecien u.s.w. etwas 
verscheiden von der typischen Art.’ The character here specially 
mentioned—and indeed all those given in the diagnosis—are not 
important enough to separate the present plant even as a variety 
from /. polygont, and are certainly not confined to the Japanese 
form, but occur on various hosts throughout Europe and North 
America. I have received, moreover, from Professor Kingo 
Miyabe a specimen labeled ‘‘ Ersyiphe polygoni DC. (= E. pisi DC. 
var. desmodu P. Henn.). On Amphicarpaea Edgeworthii var. Ja. 
ponica (not Desmodium podocarpum). Mt. Takao, Prov. Musashi, 
Oct. 8, 1899, (S. Kusano).”” It would appear, therefore, that Hen- 
nings has founded his variety on the Erysiphe on Amphicarpaea 
This specimen sent by Professor Miyabe also cannot be separated 
in any way from £. polygont. Professor Shotaro Hori has, how- 
ever, sent me examples of £. folygoni on a host-plant which is 
certainly Desmodium, viz., D. podocarpum DC. var. japonicum 
Maxim (Hakone, Prov. Sagami, Japan, coll. N. Nambu, Oct. 
30, 1900). The occurrence of the present species on Desmodium 
is interesting, as hitherto the only mildew known on Desmodium 
(D. Canadense, D. canescens, D. cuspidatum, D. paniculatum and 
Dd. sessilifolium) was Microsphaera diffusa Cooke & Peck, which 
occurs not uncommonly in the United States, but which has not 
yet been recorded from elsewhere. 
Magnus (Bericht. des naturwiss.-med. Ver. Innsbruck, 24: 
6. 1898), has recorded the occurrence of “ Sphaerotheca Castagnet 
Lév.” on leaves of Caltha palustris, from “ Schruns in Vorarlberg 
(J. Bornmiiller).” Through the kindness of Professor Magnus I 
have been able to see the original material on which the above 
record was based, and have found that the fungus in question is a 
small—or perhaps starved—form of &. polygoni, a species very 
common on many plants belonging to the Ranunculaceae (Ca/tha, 
Clematis, Ranunculus, Aqguilegia, etc., etc.). This small form of 
£. polygoni is very likely to be mistaken for S. “ Castagnet,” and 
it may be well to point out here the distinguishing characters. In 
the first place, the appendages of this form of Z. polygoni have the 
Peculiar facies of those of the examples of this species occurring 
on Clematis, Aquilegia, Ranunculus, etc., and are fewer, longer, 
slightly wider (especially towards the base) and more distinct, and 
