116 
SUMMARY OF CURRENT RESEARCHES RELATING TO 
rodlet is in any way harmful to wheat, and whether it may have any con- 
nection with “ Schmierbrand,” the author leaves undecided. 
Transformation of Bacillus tuberculosis into a common Sapro- 
phyte.* — Dr. J. Ferran succeeded, by a process of gradual acclimatisa- 
tion, in cultivating the tubercle bacillus in simple meat-broth, both at 
incubation and at ordinary temperature. Under these conditions the 
bacillus assumes cilia and becomes motile. It is thicker and the joints are 
longer. By the addition of litmus-blue-milk' sugar it was shown to pro- 
duce acid. The specific virulence is diminished so much that it takes 
5-10 ccm. to infect a guinea-pig ; the tuberculous pus from these animals 
is, however, still highly toxic. The reaction of the modified bacillus to 
the Gruber-Pfeiffer reaction shows that, while it is truly of tuberculous 
origin, yet it is closely allied to B. coli and B. typhosus. The tubercle 
bacillus of birds behaves in a similar way. The author also states that 
he has found in the fseces of man, horse, and cow, a B. coli which has the 
same staining reactions as the tubercle bacillus. Cover-glass prepara- 
tions stained by Lubimow’s method are not decolorised by 20 per cent. 
H 2 S0 4 . The bacillus loses this property on cultivation, and even in the 
frcces after some hours. 
Blood and the Identification of Bacterial Species*— Dr. A. S. 
Griinbaum, in an article on the identification of bacterial species by 
means of blood, gives an interesting summary of how serum-diagnosis 
was brought about. The chief merit is ascribed to Durham and Gruber, 
who were the first to show how valuable Pfeiffer’s reaction might be 
made. Pfeiffer first remarked the phenomenon after injecting a mixture 
of cholera vibrios together with a small quantity of serum of a cholera- 
immunised animal into the peritoneal sac of a normal animal. Durham 
and Gruber showed that the reaction occurred, not only in vivo , but also 
in vitro, and that it held good for several kinds of organisms. In the 
course of his remarks the author points out that the agglutinin is dis- 
tinct from the bactericidal and paralysing substances in immune or other 
serum ; and in considering the question it must also be borne in mind 
that the normal serum of some animals, such as man and horse, possesses 
a certain amount of agglutinative power which is approximately equal 
for at least three kinds of organisms, B. coli, V. typhosus , and V.cholerse. 
Hence it becomes a question whether the normal agglutinin becomes 
increased, or whether special ones only are produced as the result of 
infection. If the latter, then there must be an accumulation of different 
kinds of agglutinin, &c., in the blood. Presumably the latter is the 
case, for it is found necessary, in the diagnosis of typhoid, to dilute the 
serum, in order to avoid any error due to the presence of normal 
agglutinin. 
Physiology and Morphology of the Acetic Acid Bacteria.^ — The 
researches carried on by Herr W. Seifert as to the morphology and phy- 
siology of the acetic acid bacteria are on similar lines to those of A. T. 
Brown, who worked with a Bacterium aceti, an organism different in 
some respects from that called by the same name by Hansen. The 
* Barcelona, 1897. See Centralbl. Bakt. u. Par., l te Abt., xxii. (1S97) pp. 483-1. 
t Science Progress, i. (1S97) pp. 616-26. 
j Centralbl. Bakt. u. Par., 2 te Abt., iii. (1897) pp. 337-49, 385-99, 
