[HARRISON & BARLOW] NODULE ORGANISM OF THE LEGUMINOSAE 177 



Flask I. On February 7, 1905, there were 10 nodules on the 

 roots of plant 1. The largest was 2 nun. long. On April 23, there 

 were 10 nodules, 8 large and 2 small, the largest was 2x8 mm. 



Flask III. — On February 7, 1905, there were four nodules on the 

 roots of plant 3. The largest was 3 mm. long. On March 11 there 

 were eight nodules, three large and five small, the largest 1^ x 5 mm. 

 On April 22 there were eight nodules, the largest 2x4 mm. On May 

 31 there were eight nodnles, the roots were otherwise smooth. 



Flask y. On February 7, there were two nodules; March 11, five 

 nodules; April 22, six large and four small nodules; September 25, 

 six large and seven small nodules, also a general infection of the roots. 

 The largest nodule was 26 mm. long. Nine of the roots were coiled 

 at the tips. October 19th, the largest nodule was 30 mm. long and 

 2 mm. forked at the apex. A part of the nodule was green, having 

 taken on chlorophyll. The largest nodule was examined by staining 

 and only rods and no branching forms were found. Seven other no- 

 dules from this plant were examined. The bacteria were mostly rods, 

 branched forms occurred but were infrequent. A stain from the agar 

 showed numerous rods like Ps. radicicola. 



Contaminations in Flash V. — jSTo bacterial contaminations were 

 observed, but one mould colony developed by January 7th and gradually 

 spread over most of the surface of the agar. iSTo cultures were made 

 from this flask. 



Flash I, Nodule II, Plate Cultures May 31, 1905.— The nodule 

 was immersed in mercuric chloride solution 1 :1000 for one and one- 

 half minutes and plate cultures were made from it in the usual manner. 

 Typical colonies of Ps. radicicola developed, which became viscid, draw- 

 ing out in slender threads when touched with the needle. The cells 

 were like Ps. radicicola. A culture in ash-maltose-water from this 

 nodule gave a characteristic growth and branched forms were numerous. 



Plate cultures were made from the agar in Flask 1, May 31, 1905, 

 in ash-maltose-agar R78 and E77. ISTumerous colonies like Ps. radi- 

 cicola developed in twelve days, also numerous red colonies of a small 

 bacillus. 



Flash II, not inoculated. — No nodules formed on the roots as long 

 as the plant was observed. The roots became nodose or knotted by 

 March 11th and continued so. 



Plate cultures were made June 1, 1905, from flask II. These 

 developed numerous colonies of a yellow diplococcus, but no colonies 

 resembling Ps. radicicola. Plate cultures in ash-maltose-agar R78 from 

 one of the nodose roots gave numerous colonies of a. yellow diplococcus 

 but no other bacteria. 



