The Bacterial Diseases of the Bean 55 



plants, however, appeared to be the same. Considering the number of 

 species, and even of genera, that the New Jersey strain infected, it seems 

 strange that the scarlet runner remained immune. Many and repeated 

 inoculations were made on this species, however, without any positive 

 results. 



Inoculations were always made on seedlings or young plants of all 

 the species tested. Infections in all cases were similar to those occurring 

 on the Red Kidney seedlings. The disease appeared, and in several days 

 spread rapidly from the point of inoculation, and then further invasion 

 of the tissue ceased altogether. In a few cases, inoculations were made 

 on the pods of some of the above-named species. This was done by 

 pricking the tissue with a sharp-pointed instrument. The following 

 peculiarities were noted: a more-or-less water-soaked lesion occurred on 

 pods of Phaseolus lunatus, while a dry red-brown spot appeared on pods 

 of Vigna sinensis; the spots on pods of Glycine max (Plate IV, D) were 

 irregular in shape, and dark brown to almost black in color. A ring spot 

 was produced in some cases, but not in all, on pods of Dolichos lablab. 



One attempt was made to obtain infection by spraying seedlings of the 

 yard-long bean, the soybean, and the lima bean, but with no success. 



As stated above, infection was obtained in Vicia faba. This is the only 

 organism described in this memoir which attacked this species. The plants 

 which were inoculated were from 9 to 12 inches high, but the stems were 

 still succulent. Black, sunken lesions occurred at the point of injury and 

 extended up and down the stem. Leaves adjacent to the spots withered 

 and turned black, and leaves far above them turned black about the tip. 

 Although none of the plants died, they became stunted and very ragged 

 in appearance. 



ETIOLOGY 



Morphology 



The pathogene, when grown on beef-extract agar (pH 6.9), is a fairly 

 large rod with rounded ends, occurring singly or in pairs. In a few cases 

 the rod is slightly curved. A culture twenty-four hours old, grown at 

 27° C. on the above medium, with a Congo-red negative stain, had the 

 following dimensions: 2.02 M (1.35 to 3.6m) by 1.07/x (0.6 to 1.8/*). 



The organism stains readily with carbol fuchsin and gentian violet. 

 It is Gram-negative and is not acid-fast. It is actively motile, with one to 

 two polar flagella. Capsules have not been demonstrated; Huntoon's 

 method was employed for this test. 



Cultural characteristics 

 (All cultures incubated at 27° C. unless otherwise stated) 

 Beef-extract agar slants (pH 7.0). A good growth appears along the streak 

 within twenty-four hours, white to almost colorless. The growth on a 



