1895.] Root Tubercles of Leguminosae. 899 
flamed knife, and crushed out in a little sterile water, which 
was then used for cover glass preparations and for the inocu- 
lation of culture media. All staining fluids and all culture 
media were examined for the presence of germs before they 
were used, and before commencing this investigation the 
author made a preliminary one of the air of his laboratory to 
determine what germs were present and might be expected to 
appear in some of the cultures. The microscope used was a 
Leitz, which was provided with apochromatic lenses, giving a 
very clear, sharp field, up even to 2,250 diameters. The root 
sections were made in the Pathological-anatomical Institute of 
Dr. Thierfelder, and mostly by Dr. Thierfelder, himself. Several 
hundred plants were investigated, including Pisum sativum, 
Lupinus angustifolius, albus, luteus, Lathyrus tuberosus, Vicia 
faba, cracca, Phaseolus vulgaris and Trifolium incarnatum, and 
more than 300 permanent preparations were made. The in- 
vestigations finally covered the following subjects: (a) Pure 
cultures; (b) Search for the organisms in the soil; (c) Germi- 
nation of sterilized seeds in sterile sand and subsequent infec- 
tion of the plants. Cover-glass preparations, made from great 
numbers of cleaned, sterilized tubercles of Lupinus albus and 
angustifolius showed the well-known Y-shaped bodies and 
gelatine plate cultures gave two sorts of colonies, both bacilli. 
Cleaned and superficially sterilized roots were then wrapped 
in freshly sterilized cotton, put in turn into sterile netting, and 
finally covered by a fine-meshed sterile wire netting, buried 
in sterile sand and watered with sterile water. After eight 
days the plants were pulled up. Many of the tubercles were 
ruptured and the enveloping cotton was stained brown and 
swarming with pure growths of the bacteria. The sand was 
also contaminated. From this infected cotton, and also fre- 
quently from the sand, cultures were made into gelatine, 
bouillon, etc., and from these, plate cultures. The author can- 
not agree with Frank that the Y-form consists of broken down 
mycoplasma, for, upon being placed in hanging drops, these 
Y’s break up into motile bacilli and their compound nature 
can also be demonstrated by proper staining. Beyerinck, 
Prazmowski and Frank speak of one organism designated 
