18 THE BOTANICAL MAGAZINE. [Vol. xxix. No, sss. 



asci and appendages simple and clavate in shape. By the 

 peculiar form of the appendages, this fungus is distiguished 

 at once from any other genera of the family. The various 

 parts may now be described in detail. 



The fungus is parasitic on the under surface of the leaf, 

 giving a whitish dusty or "woolly appearance due to the thin 

 patches of persistent mycelium (Fig. 1). The hyphae are 

 septated, colorless, 3-4.5 p. in width, with many small granules 

 on the surface (Fig. 2). The granules are insoluble in water, 

 alcohol and potassium hydroxide, but soluble in hot water 

 and mineral acids. At certain places, the hyphae are provided 

 with appressoria which are crenulate on the margin (Fig. 3). 

 The haustoria are inconspicuous. By means of microtome 

 sections, I have observed the haustorium piercing the cell wall 

 in the shape of a very narrow tube and swell out into a bladder 

 form in the epidermal cell (Fig. 4). According to the character 

 of the haustorium, we must include this fungus in the sub-family 

 Erysipheae Palla. 



The perithecia are scattered or sub-gregarious and more or 

 less immersed in the mycelium. They are globose to globose- 

 depressed in shape, measuring 120-200 p. in diameter. The cells 

 of the perithecium are 10-20 ,u in width and the structure in 

 the upper and lower halves of the perithecium has no marked 

 difference (Fig. 5. 6. 7). 



Numerous appendages spring from the upper part of the 

 perithecium in the form of a broad ring composed of two or 

 three rows. They are simple and clavate in shape, with a close 

 resemblance to the fructification of a species belonging to the 

 genus Typhula of Basidiomycetes in their outlines, and also to 

 the immature stage of the penicillate cells of Phyllactinia. They 

 are colorless and measure 45-65 p. in length and 10—15 // in 

 width. Their walls are very thick with a thin central granular 

 protoplasmic thread. The wall, especially at the apical portion 

 undergoes a mucilaginous change. It swells up in water to a 

 slight degree but considerably in potassium hydroxide and 

 mineral acids, rupturing the wall at apex and extruding in a 

 form of round mucilaginous mass (Fig. 8-11). 



