May 20, 1910] 



SCIENCE 



791 



A careful study was made of the morphology 

 of the parasite and its relation to the host tissues. 

 These studies showed much the same conditions as 

 those reported by Hartig for this fungus on forest 

 seedlings. 



A series of careful inoculation experiments 

 were made as follows: (a) with conidia from 

 diseased plants to healthy ones, (&) with motile 

 swarm spores in water to healthy plants, (c) 

 with mycelium from pure cultures of the fungus 

 to healthy plants. 



In eveiy case there was prompt infection, with 

 the resulting lesions characteristic of the disease. 

 Microscopical examination of the diseased por- 

 tions showed the conidia and mycelium of P. 

 caotorum in abundance. 



Pure cultures of the fungus were obtained by 

 peeling back the epidermis on diseased stems and 

 transferring bits of diseased tissue to sterilized 

 bean pods. Oospores are produced abundantly in 

 cultures. The isolation of this fungus in pure 

 culture has not heretofore been aecomplished-.so 

 far as the writer knows. It is therefore the third 

 species of the genus Phytophthora to be brought 

 under cultivation. 



On the Relationship of certain Bacterial Soft- 

 rots of Vegetables: Professor W. J. Moese, 

 Maine Agricultural Experiment Station, and 

 Dr. H. A. Harding, New York Agricultural 

 Experiment Station. 



The organisms studied include several named 

 species of soft-rot bacteria, in addition to nearly 

 forty other strains isolated during the progress 

 of the investigation. They represent pathogens 

 from various cultivated vegetables, and one each 

 from the iris and calla lily, obtained from widely 

 separated sections of Europe and the United 

 States. 



The data were accumulated in two different 

 laboratories, extending over a period of several 

 years, and the more important determinations 

 were checlced by four different workers. Some 

 12,000 subcultures were used and over 1,500 fer- 

 mentation tube tests made, resulting in the con- 

 clusion that the organisms comprising the group 

 are identical in all morphological, cultural, phys- 

 ical and biochemical features except in ability to 

 ferment dextrose, lactose and saccharose. 



An almost complete series of organisms was 

 obtained, showing all except two of the possible 

 combinations of fermentative ability from an 

 organism which regularly produced visible gas in 

 fermentation tubes containing any one of the 

 three carbohydrates mentioned to one which never 



produced visible gas from either of them. While 

 the final decision as to classification is reserved 

 till work upon the pathogenicity of the various 

 strains or described species is completed, the 

 writers feel that based on the bacteriological 

 studies alone the group should be considered as 

 one somewhat variable species of which Bacillus 

 carotovorus Jones is the earliest described and 

 should therefore be considered as the type. 



(Data to appear as Technical Bulletin 11 of the 

 >Jew York Experiment Station, and in the Twenty- 

 first Annual Report of the Vermont Experiment 

 Station.) 

 Timothy Rust in the United States: Mr. Edw. C. 



Johnson, Bureau of Plant Industry. 



Timothy rust was reported in the United States 

 by Trelease as early as 1882. Pammel reported 

 it from Iowa in 1891. From 1891 to 1906 ho 

 mention of the parasite in the United States has 

 been found. In 1906 the rust became epidemic 

 in the timothy-breeding plats at the Arlington 

 Experiment Farm, Virginia. Since then the rust 

 has been common in many localities. It has been 

 reported from all the states east of the Mississippi 

 and north of Tennessee with the exception of the 

 New England states, New Jersey and Illinois, and 

 from Minnesota and Iowa. 



The rust is similar in general appearance and 

 morphological characteristics to Puccinia gram- 

 inis Pers., on wheat. Its aecial stage is not defi- 

 nitely known in this country. Eriksson and 

 Henning, working with a rust on timothy in 

 Sweden, were able to produce secia on barberries 

 once in nine trials, and that only in one place of 

 inoculation against 92 places inoculated with 

 negative results. In trials in 1895 they again 

 were unsuccessful in 25 inoculations on bar- 

 berries. They concluded that the rust is a dis- 

 tinct species and named it Pucmnia Phlei-pra- 

 tensis. Kern considers it "a race of Puccinia 

 poculiformis (graminis) or a so-called physiolog- 

 ical species." 



Inoculation experiments with timothy rust on 

 various grasses in the greenhouses at Washington, 

 D. C, demonstrate that the rust in the United 

 States and the rust in Europe are identical, and 

 that the species is not well fixed. The rust trans- 

 fers easily to Avena sativa, Seoale cereale, Fes- 

 tuca elatior, Daotylis glomerata, Arrhenatherum 

 elatius and Poa compressa. Inoculations directly 

 on Triticum vulgare and Hordeum vulgare give 

 negative results. 



Timothy plants brought into the greenhouse 

 from Arlington Experiment Farm, Virginia, Jan- 



