ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 
85 
increased toxicity of mixed cultivations of diphtheria bacilli and Strep- 
tococci, micro-organisms invariably associated in diphtheritic membrane. 
Whether the substance which is precipitablo from its aqueous solution 
by means of alcohol is an albumoso or not is left undetermined. 
Streptococcus obtained from the Blood of a Scarlet Fever Patient.* 
— MM. d’Espine and Marignac obtained from the blood of a scarlet 
fever patient a pure cultivation of a Streptococcus which presented 
clear differences from St. pyogenes and from the short Streptococcus of 
Lingelsheim. The question whether this microbe has any aetiological 
significance for scarlet fever is left undecided, as inoculation experiments 
on human beings are prohibited. 
Bacterium coli commune.f — MM. Lesage and Macaigne have been 
carrying on experiments relative to the virulence of intestinal bacteria. 
B. coli commune did not show that it was pathogenic to animals, although 
it had been derived from a man suffering from diarrhoea. 
Diarrhoea, for example the simple diarrhoea of children, say the 
authors, makes B. coli commune virulent. In cases where no diarrhoea 
has existed B. coli commune does not migrate during the first twenty- 
four hours after death into the organs of the body, although it does so 
if there have been diarrhoea, ulceration of the intestine, or pulmonary 
disorder. Besides this harmless B. coli commune , which the authors 
consider a saprophyte, B. coli septicum, an organism of great virulence, 
and B. coli pyogenes , not quite so virulent, are found in the intestine of 
sick persons. 
B. coli cholerigenes, isolated by Gilbert and Girod in several cases of 
cholera nostras, both in adults and children, is a very virulent organism, 
and preserves its power for seven months. The more severe the case 
the more frequent became the presence of this micro-organism, while in 
less severe cases several other bacteria accompanied it. 
Differential Characters of Bacterium coli commune and Bacillus 
typhosus. t — According to M. E. Tavel the following differences exist 
between B. coli commune and B. typhosus : — (1) The former only exhibits 
molecular movements, the latter shows lively spontaneous movements. 
(2) On grape-sugar-agar the first forms gas, the latter none. (3) The 
former imparts a slight red colour to bouillon and clouds it strongly, 
with the latter it remains pale yellow and never shows a scum. (4) On 
potatoes the former forms a thick grey-yellow culture, the potato 
becoming greyish-brown ; the typhoid bacillus produces scarcely visible 
colonies, and the colour of the potato remains unchanged. (5) The 
typhoid bacillus has flagella, B. coli commune none. The author is 
of opinion that the careful and judicious use of these criteria will 
enable a differential diagnosis between these two micro-organisms to be 
made. 
* La Semaine Med., 1892, No. 29. See Centralbl. f. Bakteriol. u. Parasitenk., 
xii. (1892) p. 157. 
t La Semaine Med., 1892, p. 40. See Centralbl. f. Bakteriol. u. Parasitenk , xii. 
(1892) p. 257 
X La Semaine Med,, 1892, p. 52. See Centralbl. f. Bakteriol. u. Parasitenk., xii. 
(1892) pp. 256-7. 
