334 ANNALS OF THE MISSOURI BOTANICAL GARDEN 



[Vol. 9 



he also states (p. 4), are attacked by 14 different disease produ- 

 cers. Not having mentioned these by name or by citation to 

 literature, it becomes rather difficult to ascertain the organisms 

 which he included. It is quite possible that 1 or more of these 14 

 have not as yet appeared in print and are known only to Dr. 

 Smith. Of the host genera which he lists, no reference has been 

 found to a bacterial disease of Bromus, and aside from Manns' 

 (I, '09) brief reference to a disease on the blue grasses which, 

 according to the author, appeared to be the same disease as that 

 on oats, no other literature dealing with a bacterial disease of 

 Poa has been found. Concerning a bacterial disease of Phleum 

 but little more information is available. Manns refers to a bac- 

 terial disease of timothy in the same sentence, cited above, in 

 which reference is also made to a disease of Poa. In addition 

 to this reference, a blade blight of timothy "apparently bacterial" 

 was reported in Ohio during 1918 and 1919 by the Plant Disease 

 Survey (I, '19, p. 157, and '20, p. 7C>), and Jones, Johnson, and 

 Reddy (I, '17) mention a bacterial disease of Phleum pratense. 



Of the bacterial diseases of grasses which are well known or 

 supposedly well known it will perhaps be desirable to characterize 

 briefly each one, noting the similarities and the differences as 

 compared with the foxtail organism. A chronological sequence 

 will be followed. 



One of the very first investigators of bacteria in relation to 

 plant disease and perhaps the first to study carefully a bacterial 

 disease of a grass was Prillieux. His account of a rose-red disease 

 of wheat kernels (I, 78) is well known. He made no pure cul- 

 ture studies, so that it is not possible to identify definitely the 

 organism he described. Gentner (I, '20) has recently published 

 an account of a bacterial disease of barley in which he states 

 that the pathogen when inoculated in pure culture into sterilized 



kernels of barley, wheat, and corn produces a reddish discolora- 

 tion. He believes that the organism with which he worked, a 

 rod-shaped, red-pigment producer, named by him Bacillus ce- 

 realium, is the same as Prillieux's organism and that the Micro- 

 coccus which Prillieux found associated with discolored wheat 

 kernels represents the spore stage of B. cerealium. The fact that 

 this organism produces a red pigment on various media and is a 

 spore producer, an anomaly among plant pathogens, would im- 

 mediately distinguish it from the foxtail organism. 



