900 The American Naturalist. [October, 
variously as Bacillus radicicola, Bacterium radicicola, and Rhiz- 
bium leguminosarum. Gonnermann thinks that there are 
several germs capable of causing these galls. He calls his 
organisms Bacillus tuberigenus, 1, 2, 3, etc., having isolated no 
no less than seven varieties, not including two micrococci. All 
of these are characterized, but not as fully asthe present state 
of bacteriology requires. Beyerinck’s B. radicicola was not 
found. Soil examinations were begun at Rostock. Earth was 
scattered on gelatine plates, and soil from lupine fields was 
washed with sterile water and cultures made from this. By 
these methods four of the kinds already isolated from the 
tubercles made their appearance and were cultivated out and 
their identity established. The most abundant organism in 
the Rostock fields was Bacillus fluorescens non liquefaciens, then 
followed B. tuberigenus, No. 3. This is a motile organism, 0.3 
by 0.6, united in 2’s or more, bright red-brown on potato, 
yellow-brown or brownish and fine granular on gelatine plates, 
and able to liquify gelatine rapidly. Winter examinations of 
earth were made for spores. In soil taken from Rostock, in 
February, not a living bacterium could be found, but there 
_were numerous spores. This soil was shaken up with sterile 
water, and the coarsest parts allowed to settle as sediment I. 
The cloudy fluid was poured off into a sterile test-tube and 
allowed to settle for a minute to get sediment II. Sediments 
III and IV were obtained in the same manner, the latter con- 
sisting of the finest silt. Cover-glass preparations were made 
from each sediment and stained with gentian violet for the 
identification of bacteria, while for spores a corresponding 
series was dry-heated to 150°C., and then exposed for an hour 
to boiling carbol fuchsin, washed in alcohol, and afterward, in 
some cases, faintly stained with methyl blue. Finally, plate 
cultures were made from each sediment. Sediment I contained 
numerous bacilli, 4-9, by 0.5-0.6z, each bearing 2-6 spores. No 
bacteria free from spores could be found, but plate cultures 
gave many colonies. No such large bacilli were found in the 
earth in summer. In sediment II, spore-bearing bacilli were 
few, but plate cultures yielded many colonies, thus showing 
the presence of spores. In sediment III, dead Y-forms first 
