[Vol. 9 



338 ANNALS OF THE MISSOURI BOTANICAL GARDEN 



bohydrates, and produces strong diastatic action, characters quite 

 different from those described for P. Avenae. 



Miss Elliott was kind enough to send the writer a culture of 

 Bacterium coronafaciens, the causal agent of the halo-blight of 

 oats, and comparison of this organism with the foxtail pathogen 

 shows distinct differences. As Miss Elliott states, B. coronafa- 

 ciens usually occurs in chains and produces a brownish color on 

 nutrient agar; these characters serve to distinguish it imme- 

 diately from the foxtail organism, which usually occurs singly 

 or in pairs and produces no brown color on nutrient agar. There 

 are also a number of other morphological and physiological dif- 

 ferences which can be readily ascertained by comparing the de- 

 scription of the foxtail organism given below with the one given 

 by Miss Elliott (I, ? 20). Before closing the reference to bacterial 

 diseases of oats the writer wishes to call attention to a pathogen 

 isolated by him from reddish spots of oats, an organism which 

 when inoculated in pure culture, produced the same kind of spots 

 (no halos are produced). This organism, a white, monotrichous 

 rod, is a strong gelatin liquefier and does not attack foxtail. It 

 apparently is not Bacterium coronafaciens. 



A bacterial disease of western wheat-grass was described by 

 O'Gara in 1915 (I, '15, *15 a ). The pathogen, Aplanobactcr Agro- 

 pyri, is yellow and non-motile and thus quite different from the 

 foxtail organism. 



In 1916 Jones, Johnson, and Reddy briefly described a bacterial 

 blight of barley and certain other cereals. This was followed by 

 a more complete description in 1917. In this, also, a yellow or- 

 ganism, Bacterium iranslucens, is involved. Besides barley, these 

 writers have found that w T heat, spelt, rye, timothy, and* oats are 

 attacked by similar bacterial diseases, but that the barley or- 

 ganism, B. translucens, does not attack the other grasses listed 

 above. Attention has already been called to a bacterial disease 

 of barley found in Germany by Gentner (I, '20). While proof 

 has been given that Bacillus cerealium may produce disintegra- 

 tion of seed, it seems to me that more work would be necessary be- 

 fore any conclusion could be drawn regarding the production of 

 brown spots on various organs of the barley plant. As indicated 

 previously the organism differs greatly from the foxtail pathogen. 



A new disease of wheat, now well known as black chaff, was 

 first described by Smith in 1917. The pathogen is closely related 

 to the one causing barley blight and has been named by Smith, 



