198 Urocystis. 



On Secale cereale L. — Eye. 



Victoria — On plants infected with spores from Germany. 

 On Lolium perenne L. — Rye-grass. 



Victoria— Myrniong, Nov., 1899 (Brittlebank). 

 On Poa caespitosa Forst. — Tussock-grass. 



Victoria — Kergunyah, Nov., 1902 (Eobinson). 



This is the well-known Rye smut, although it has not been met with natu- 

 rally on this host in Australia. Through the courtesy of P. Sydow, I received 

 fresh specimens from Germany. The spores are of a dark golden-brown 

 colour, and 1-3 in each spore-ball are fairly common, while 4-5 are rather 

 exceptional. The spores are either completely or often incompletely invested 

 by sterile cells, which are generally of a yellowish tint, oblong to oval, with 

 distended and regularly thickened walls. 



Germination. — According to Brefeld^, the spores germinate readily in 

 water, giving rise to a longer or shorter germinal tube, and producing a 

 whorl of 4-6 conidia at the apex. The promycelium may become septate, 

 and the' conidia grow out into long branches, septate towards the basal end. 



In a nutritive solution germination occurred in a similar fashion, only the 

 whorl of conidia grew more luxuriantly and became branched just like a 

 mycelium. 



I also germinated the spores in tap water, and the promycelium was 

 invariably short, never longer than the conidia, and always unicellular. The 

 cylindrical conidia formed a whorl of 3-4 at the apex, close together at first 

 but gradually diverging. The average size was 12-15 x 3-4 yit, but sometimes 

 they reached a length of 24 /(. Germination occurred both on a microscopic 

 slide and floating on water in a watch-glass. 



These spores were obtained from Rye plants grown in my garden, but in 

 a previous germination I used spores obtained from Berlin. They were 

 placed on a slide in tap-water, and they germinated freely the third day, 

 producing a whorl of 2-6 conidia at the apex of the promycelium, which 

 varied considerably in length, and was finally 4-5 septate. 



(Plates v., LI.) 



Stipa. 

 66. Urocystis stipae McAlp. 



Sori in leaves, leaf-sheaths, and stems, forming elongated dark-coloured 

 streaks, at first covered by the epidermis, but ultimately becoming 

 free by the rupture or decay of the covering. 



Spore-balls exceedingly variable in shape and size, globose, ellipti- 

 cal, oblong, or polygonal, light golden-brown, 22-32 ^ diam., or 

 28-40 X 20-32 /<. " 



Spores round to oval smooth, 1-5 in a ball, average 3, 12-16 x 

 9-12 i-i ; sterile peripheral cells forming a single interrupted or com- 

 pletely investing layer, pale-yellowish, flattened oval, 8-12 /( long. 



