I.'ifc Histoties of 1 anoiis Grass Sinais. 



over a large portion of their bodies from the spores, clouds of which rise in 



the air as the flock Wd,lks through the grass, and yet, accordhig to Brefeld, 



it is rarely found on this species in Europe. 



It is also sometimes very bad on the prairi? 



grass, not only destroying the grains but 



even the base of the glumes (Plate XV.)- 



In the early part of 1907 the attack was 



particularly severe, and in some paddocks of 



this grass every plant was infected. 



In 1908 it became something of the nature 

 of an epidemic, and this splendid winter fodder 

 grass, the seed of which is now on sale in 

 Britain for this purpose, was very badly 

 affected in various districts of Victoria, where 

 it forms the principal pasturage. How it is 

 spread may be seen from the accompanying 

 figure, which shows a sample of seed brought 

 under my notice when the farmer found all 

 his crop smutted. On visiting this paddock 

 I found that not a single plant had escaped, 

 and recommended burning to destroy the 

 spores. But the farmer preferred to utilize it 

 as fodder, and so turned his cows into it, and 

 they also fed upon the cut hay without anv 

 seemingly injurious effects. Such diseased 

 plants have sometimes been reported to be 

 poisonous, but they were evidently not so in 

 this instance. This was in 1907; and last year 

 he informed me that any heads which sprung 

 from the self-sown grass were just as smutty 

 as before. It will be rather a difficult task to 

 get rid of it now, seeing that the spores retain 

 their vitality for years, but root and other 

 crops are being grown instead of grass. The 

 seed referred to was sold to the farmer by 

 leading seedsman, and such a case emphasizes 

 the necessity for some means of preventing 

 such seed being sold without inspection. 



At first the glumes are leaden-coloured and 

 enclose the spores, but the glumes gradually 

 become disrupted and allow the spores to 

 escape. Occasionally in the prairie grass 

 several stalks are found springing from the 

 same root, of which one may be quite free from smut, while the others are 

 diseased. 



Germination. 



The spore germinates freely in water, and retains its germinating power 

 for some time. I gathered soft brome with this smut in November, 1904, 

 and in July, 190(5, it was still capable of germination. Then in May, 1907, 

 spores from the same plant germinated in water, so that they still retained 

 their germinating power for at least two and a-half years. The spores put 

 forth a small germ-tube or promycelium, and this bears at its apex a conidium, 

 which is soon detached. The conidia are colourless, elongated, cylindrical, 

 flat at attached end, rounded at free end, 13 - 17 x 3- 4 //. 



nitidii of panicle 

 spikclets at base 

 V at top. 



