428 
SUMMARY OF CURRENT RESEARCHES RELATING TO 
not a true fungus, but forms, with those which produce the root-tubercles 
of the Leguminosae, a distinct group of Schizomycetes, forming a con- 
necting link with the Fungi, and characterised by the formation of 
sporanges. The organism enters the host-plant through the root-hairs. 
Inside each hair is a mucilaginous thread in which the organisms lie 
imbedded. Before reachiug the root itself, this mucilaginous mass be- 
comes filamentous, and resembles mycelial threads. Within the root the 
masses of mucilage resemble plasmodes, which extend from cell to cell, 
and ultimately become of a spongy consistency, from the appearance of 
numerous vacuoles surrounded by thin walls of mucilage, in which lie 
the organisms, now more or less in the form of filaments. Very soon 
after the formation of a tubercle, these organisms change into spheres 
filled with nitrogenous matter which rapidly develops into spores ; in 
other words, they become sporanges. The spores germinate rapidly,, 
forming short rods which fill the cells of the tubercle, but do not 
develop mucilage. 
Mosaic Disease of the Tobacco Plant. — Herr D. Iwanowski* states 
that Beijerinck’s views on the mosaic disease of the tobacco plant are 
erroneous, inasmuch as two distinct diseases have been confused and one 
has been made a phase of the other. The mosaic and pock diseases, 
though not infrequently met with in the same plant, often occur sepa- 
rately ; and while the mosaic is an infectious malady, the pock is not. By 
artificially inducing rapid transpiration, the pock disease may be imparted 
to healthy plants in a few days. Seven years ago the writer filtered the 
juice of plants infected with mosaic disease, and found that the filtrate 
retained its infective propeity for months. He had also observed that 
infected leaves, even when kept in 95 per cent, alcohol, retained their 
infective power for 10 months. Recently the author has obtained some 
evidence to show that the disorder is bacterial, but he merely states 
that some cultivations gave positive results when inoculated on healthy 
plants. 
Prof. W. Beijerinck f concedes Herr D. Iwanowski’s claim to priority 
in using the porcelain filter to obtain a germ-free juice expressed from 
infected tobacco leaves. The writer defends his position as to the pock 
disease and some other details. 
New Acid-resisting Bacillus.^ — Dr. 0. Korn describes a bacillus 
which has much resemblance to the tubercle bacillus on the one hand, 
and to the pseudo-tubercle bacilli (butter, timothy grass, and dung bacilli) 
on the other. Like the bacilli of Petri and Rabinowitsch, the original 
source of the new organism was butter, and it was obtained through the 
intermediation of a guinea-pig. The deposits much resembled those 
of tuberculosis, that is to say, there were caseous masses in different 
parts and organs, notably in the lymphatic glands. The organism was 
readily cultivable in the ordinary media at room as well as at incubation 
temperature. There were morphological differences according to the 
media, the shape varying from that of B. coli communis to a Coccothrix 
form. The bacillus was easily stainable, even by Grain’s method, but 
* Centralbl. Bakt. u. Par., 2 te Abt., v. (1899) pp. 250-4 (2 figs.). 
t Tom. cit., pp. 310-11. 
X Centralbl. Bakt. u. Par., l te Alt., xxv. (1899) pp. 532-41. 
