ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 
521 
tion of this chronic form, but afterwards the author was able to confirm 
the results of Salmon and Smith. Inoculations from the organs, 
especially the diseased intestines and mesenteric glands, disclosed a 
bacterium resembling that of 1887, but which was not pathogenic to 
mice or rabbits. It became evident from feeding pigs that it was a less 
virulent variety of swine-plague. The pigs sickened, and if killed after 
nine days croupous inflammation of intestines was found ; if killed later, 
small wounds and scars, close to the croupous membranes. When mice 
and rabbits were inoculated from pigs which were sick or dead of swine- 
plague, they usually died, but the swine plague bacterium was not found ; 
but in the exudation from serous membranes, in the blood and in the 
spleen, a bacterium, called by the author “ Vakuolebacillus,” was 
present. In the blood these bacilli showed as oval corpuscles, the 
poles only staining. In the exudation from serous membranes they 
were seen as plump little bodies, at one end of which was a vesicle. 
Experiments with the vacuole bacillus showed that its pathogenic 
action set up a fatal pleuro-pneumonia, but there was no affection of 
the intestinal tract. The vacuole bacillus is therefore undoubtedly 
identical with the swine-plague bacillus of Salmon and Smith, and 
certain forms of swine-plague are to be regarded as cases of 
mixed infection ; that is to say, hog-cholera and swine-plague may be 
simultaneously present in the same animal. Besides the specific organism 
of swine-plague another micro-organism, the necrosis bacillus, is very 
constant in the chronic form of this disease. It would appear that this 
exists in the intestine of healthy swine, but after the intestinal wall is 
weakened by the croupous inflammation it invades the deeper lying 
parts, producing there profound necrotic processes. The author main- 
tains that, (1) swine-plague is caused by a specific micro-organism ; 
(2) the pneumonias occurring in the chronic form of this disease are 
set up by another bacterium which apparently inhabits the nasal 
secretion of healthy pigs ; (3) the profound necrotic changes in the 
intestinal canal, as well as the necrotic foci in the pneumonic lungs, are 
due to the invasion of the necrosis bacillus. 
Pathogenic Action of Bacillus lactis.* — MM. R. Wurtz and R. 
Leudet, during some experiments relative to the pathogenic action of 
Bacillus lactis, established the fact that the characteristic claimed by 
Escherich as being distinctive of B. lactis aerogenes — fermentation in 
absence of air — was shared by Bacillus lactis. The two bacilli were 
therefore possibly identical. Guinea-pigs and rabbits inoculated with 
this bacillus died in a short time from severe diarrhoea with emaciation. 
On post mortem examination, well-marked ulcerative gastro- enteritis 
was discovered. The same, though less severe, changes were produced 
by the injection of sterilized cultivations. The toxic action appears to 
be dependent on the presence of proteids in the nutrient media, as bacilli 
cultivated on non-albuminous media exerted a much less pathogenic 
action, and this action is much diminished by heating. The toxin was 
not isolated. Cultivations in peptonized bouillon or alkaline pepton- 
solutions always became strongly alkaline, ammonia and other foetid 
substances being formed. The indol reaction was negative. 
* Arch. Med. Exp. et d’Anat. Pathol., iii. No. 4. See Centralbl. f. Bakteriol. u. 
Parasitenk., xiii. (1893) pp. 275-6. 
