I BACTERIUM ICTEROIDES. 257 



Sanarelli rests the principal evidence as to the signifl- 

 nce of the organism upon the following: 

 1. He found it in 58% of cases (the dead bodies). 

 l 2. Germ-free filtrate of cultures is claimed to produce 

 in man the entire typical complex of a case of yellow fever. 



3. Serum from cases of yellow fever causes agglutination 

 of the Bact. icteroides. Serum from animals which are 

 immunized against the Bact. icteroides is said to operate 

 prophylactically and therapeutically against yellow fever. 



4. The B. icteroides is pathogenic for mice, guinea-pigs, 

 rabbits, goats, and sheep. Intravenous injections are 

 followed by vomiting, and bloody enteritis, scanty albu- 

 minous urine, and once ( ! ) marked icterus. 



5. The pathologic changes in the inoculated animal 

 correspond to those of yellow fever. Often extreme fatty 

 degeneration of the liver occurs. The most convincing 

 preparations are obtained from the dog. 



Also Foa (C. B. xxiv, 890) finds grave specific changes 

 in the bone-marrow of animals: fibrinous thrombosis of 

 the peripheral vessels, necrobiotic areas, etc. 



We cannot yet look upon these proofs as completely 

 sufficient. While no objection to its pathogenic signifi- 

 cance is to be found in the fact that especially sharp pecu- 

 liarities are not possessed by the Bact. icteroides, — one 

 only has to remember the characterization of the Vibrio 

 cholera? as compared with water vibrios, or the similarity 

 between the Bact. typhi and Bact. coli, — still it is to be 

 admitted that certain varieties of the Bact. coli are also 

 found in many cadavers and may produce similar disease 

 symptoms in animals. It appears also objectionable that 

 yellow fever is a typical disease of the warm zone, and 

 ceases in places and at times with lower temperature, 

 while the B. icteroides possessed about the same resist- 

 ance as the B. coli to lower temperature. Yet this can 

 also be understood, since the cold may operate upon the 

 intermediate host, carrier, etc. 



Bacterium alcaligenes. (Petruschky.) L. and N. 



Bacillus faecalis alcaligenes Petruschky. (C. B. xix, 

 187.) 



17 



