October 29, 1915] 



SCIENCE 



617 



between them. Sections of the spikelets show 

 that the floral organs are extensively occupied 

 by the bacterial organism which may be found 

 filling the spaces between them. The disease 

 seems to be that of the upper portion of the 

 plant and has not been found on the roots or 

 lower internodes and sheaths. There is pro- 

 duced a premature drying and bleaching of all 

 the parts of the plant covered by the bacterial 

 ooze. When the bacterial slime hardens it may 

 be separated from the plant surface in the form 

 of thin, lemon-yellow flakes. 



At room temperature (25° C. =t) the organ- 

 ism grows very slowly on nutrient neutral agar. 

 Plates that were thickly sown did not begin to 

 show growth until the eighth day, while very 

 thinly sown plates produced no bacterial col- 

 onies. However, the organism grows promptly 

 on cooked potato, producing a viscid, lemon- 

 yellow growth at the end of about the sixth 

 day, but growth is apparent by the end of the 

 second day. Organisms taken from a two-day 

 cooked potato culture and stained with carbol- 

 fuchsin, are about twice as long as broad and 

 occur singly or in pairs joined end to end. A 

 white organism which grows readily in agar is 

 frequently found associated with the yellow 

 organism. 



This disease of western wheat-grass has 

 many characteristics in common with Eathay'a 

 disease of orchard grass (Dactylis glomerata, 

 L.) caused by Aplanoiacter rathayi, E. F. S., 

 and described by Eathay^ and later by Smith.^ 



First : The characteristic viscid, lemon-yellow 

 slime forming layers over the uppermost 

 leaves, the upper internodes and the different 

 parts of tke inflorescence is common in both 

 dieases. 



Second: The injury to the plants is due to 

 the bacterial growth which first develops con- 

 spicuously on the surface and only later pene- 

 trates into the interior. 



Third: The bacterial organism in both dis- 



1 Eathay, Emerieh, ' ' Ueber eine Bakteriose von 

 Dactylis glomerata L.," Sitzber. der Wiener ATcad., 

 1 Abth., Bd. CVIII., pp. 597-602, 1889. 



2 Smith, Erwin F., "A New Type of Bacterial 

 Disease," Science, N. S., Vol. XXXVIIL, No. 

 991, Dee. 26, 1913. "Bacteria in Eelation to 

 Plant Diseases," Vol. III., August 4, 1914. 



eases produces a characteristic lemon-yellow 

 growth. 



Fourth: The best growth is made upon 

 cooked potato ; growth on agar is very slow and 

 unless the organism is thickly sown growth 

 does not readily take place. 



Fifth: A white organism which readily 

 grows on agar is frequently associated with 

 the yellow organism in both diseases. 



An extended study of the disease and the 

 causative organism is in progress and the re- 

 sults will be published later. 



P. J. O'Gara 

 Department of Agricultural Investigations, 

 American Smelting & EEriNiNG Company, 

 Salt Lake City, Utah, 

 July 13, 1915 



MEFOMT OF THE SAN FRANCISCO MEET- 

 INGS OF SECTION F OF THE AMERI- 

 CAN ASSOCIATION FOR THE 

 ADVANCEMENT OF 

 SCIENCE 

 The opening session was held on Monday morn- 

 ing, August second, in San Francisco, in joint 

 meeting with all other sections to listen to ad- 

 dresses of welcome and the address of the presi- 

 dent of the Pacific Coast Division of the Ameri- 

 can Association for the Advancement of Science, 

 Dr. W. W. Campbell. 



In the afternoon, the Section adjourned to the 

 University of California, Berkeley, where, in con- 

 junction with the American Society of Natural- 

 ists and the American Society of Zoologists, the 

 following papers were read. 



On Wednesday, August 4, the affiliated societies 

 made an excursion to Stanford University, at 

 Palo Alto, and in the afternoon held a joint ses- 

 sion with the American Genetic Association and 

 the Eugenics Research Association. 



The program for the San Francisco meetings 

 was arranged by the following committee: 



committee on program 



Charles A. Kofoid, chairman. University of 

 California; Barton W. Evermann, California Acad- 

 emy of Sciences, San Francisco; C. H. Gilbert, 

 Stanford University; Joseph Grinnell, University 

 of California; S. J. Holmes, University of Cali- 

 fornia; Vernon L. Kellogg, Stanford University; 

 William E. Ritter, University of California; Harry 

 Beal Torrey, Reed College, Portland. 



John F. Bovard, 

 Acting Secretary for Section F 



