ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 
495 
comparing data obtained on the second or third day of cultivation with 
those of the eighth or fifteenth. 
Pigment production of Bacillus pyocyaneus in Symbiosis with 
other Organisms.* — Herren It. Miihsam and C. Schimmelbusch point out 
that it has been known for a long time that the access of air, the nutrient 
medium, and the idiosyncrasy of the bacilli, are of extreme importance 
for the development and quality of the pigment formed by B. pyocyaneus ; 
and these authors show that this pigment formation is influenced by 
symbiosis with other micro-organisms. Pyocyaneus in association with 
St. pyogenes , Tetragenus , Anthrax , Aspergillus fumigatus, Oidium lactis, 
and a fungus from sour milk, loses its chromogenic property entirely or 
nearly so. Green Pyocyaneus cultivations when inoculated with St. 
aureus , St. tetragenus , bacilli of sour milk, lose colour. When Pyo- 
cyaneus is inoculated on cultivations of Staphylococci , Anthrax or Tetra- 
genus , a green colour will develope, but this soon disappears, and this loss 
of the colour-producing power is not ascribable to death of the bacilli, 
nor to any change in the reaction of the medium. Hence the alteration 
is not due to any simple chemical change, and the explanation requires 
further observation. 
Physiological Effect of Metabolic Products of B. Hydrophilus 
fuscus.f — Bacillus hydrophilus fuscus is an organism pathogenic to 
frogs. It resembles the bacillus of enteric fever, is easily stained by 
anilin dyes, is decolorized by Gram, grows on the usual media, does not 
liquefy gelatin, thrives well at the body temperature, and is pathogenic 
to numerous animals. The metabolic products of this organism have 
been examined by Dr. A. Trambusti, who found that the best way to 
isolate them was to precipitate with absolute alcohol, for by this means 
two groups of substances are at once separated, one precipitated, one 
remaining in solution. Experiments made with the soluble products of 
this organism come under three categories : physiological effect ( l) of 
the pure culture ; (2) of substances precipitated by alcohol ; (3) of pro- 
ducts soluble in alcohol. 
The experiments had reference mainly to the effect on nerves and 
muscles, and the heart. The products of Hydrophilus fuscus were found 
to be divisible into two groups, one of which had a paralytic effect, and 
the other an exciting action on the muscles, nerves, and heart, and thus 
having some resemblance to caffein and veratrin. There exist there- 
fore in these products two substances having antagonistic physiological 
action. 
Intracellular Bacterial Poisons.^ — Comparatively recently Dr. E. 
Kle^ brought forward evidence to show that certain pathogenic organisms, 
Cholera vibrio, Vibrio Finhler, Bacillus prodigiosus, coli, and typho- 
sus, and also Proteus vulgaris , contained within their cell-substance the 
same poison, and this, when injected into the peritoneal sac of guinea- 
pigs, produced the same symptoms and the same pathological changes. 
* Arch. f. Klin. Chirurg., xlvi. (1893) No. 4. See Centralbl. f. Bakteriol. u. 
Parasitenk., xv. (1894) p. 430. 
t Beitr, z. Pathol. Anat. u. Allgem. Pathol., xiv. (1893) No. 2. See Centralbl. 
f. Bakteriol. u. Parasitenk., xv. (1894) pp. 607-8. 
I Centralbl. f. Bakteriol. u. Parasitenk., xv. (1894) pp. 598-601. 
