anata diittine eee 
NOTES ON THE ERYSIPHACEAE ~ 21 
also by directly increasing the germinating powers of the spores of 
the parasitic fungus. Eriksson (‘Ueber die Forderung der Pilz- 
sporenkeimung durch Kalte,’’ Centralbl. fiir Bakter. und Para- 
sitenk. I: 557-565. 1887) has also experimented on the same 
lines with regard to the germination of uredospores, and found 
that cooling down to freezing point had a favorable influence on 
their germinating powers. 
As Zopf (go) has pointed out, bodies of a definite shape are 
found in the cell-contents of the conidia of certain species of the 
Erysiphaceae. These bodies are composed of a substance which 
Zopf calls fibrosin, and which he states to be almost indistinguish- 
able in its reactions from fungus cellulose. The bodies are minute, 
the largest measuring 6-8 in the greatest diameter, and are of 
varied shape, flattened discs, conical and hollow, or cylindrical. 
These fibrosin bodies belong to the group of carbohydrates, and 
according to Zopf function as reserve material ; he observed that 
on the germination of the conidia the fibrosin bodies were gradu- 
ally absorbed. They were first observed in the conidia of Podo- 
Sphaera oxyacanthae, but were also seen by Zopf in Sphaerotheca 
and in some species of Erysiphe. Neger (54) has observed them 
well-developed in the conidia of species of Uncinula, but states 
that in Microsphaera they appear to be absent or almost too small 
to be visible. Zopf’s statement, however, that these fibrosin bodies 
constitute the only case known in fungi in which a carbohydrate 
Serves as reserve material—in the place of fat or oil—is erroneous, 
as other carbohydrates are known to occur not uncommonly (see 
Errere in Ber. deutsch. bot. Gesellsch. 5: Ixxvi. 1887). 
Harper in an important paper in the Annals of Botany (25), 
in which the question of relationship of the Erysiphaceae to other 
fungi is discussed, replies in detail to the article of Dangeard 
(14) in which an attempt is made to discredit Harper’s previously 
published account of the development of the perithecium in 
Sphacrotheca. 
I am indebted to the following botanists for kindly sending me 
specimens : Professor J.C. Arthur, Mme. J. E. Bommer, Professor 
F. Bubak, Professor A. Magoécsy-Dietz, Mr. E. M. Freeman, Dr. 
J. Feltgen, Dr. D. Griffiths, Dr. P. Hennings, Professor Shotaro- 
Hori, Professor A. Jaczewski, Professor A. Kitmanoff, Dr. E. 
