iro 



NOT DESCRIBED IN PREVIOUS SECTIONS. 523 



11 chloride a characteristic color reaction an intense red color. Sieber 

 has obtained from his cultures an extremely toxic alkaloid in the form of a 

 hydrochlorate. Two litres of filtered culture gave 0.1 gramme of this salt. 

 An aqueous solution of this killed a frog in fifteen minutes in the dose of 

 0.0035 gramme. 



168. BACILLUS OF MERESHKOWSKY. 



Obtained by Mereshkowsky (1894) from infected animals (Spermophilus 

 musicus) which died from an epidemic malady developed in his laboratory. 



Morphology. Closely resembles Loffler's Bacillus typhi murium. 



Biological Characters. An aerobic, motile, non-liquefying bacillus. 

 Spore formation not observed. Grows in the usual culture media at the 

 room temperature best at 37.5 C. In bouillon, at the end of twenty-four 

 hours, the medium is clouded and a white pellicle is seen upon the surface, 

 which breaks up into small flocculi and falls to the bottom when the tube 

 is slightly shaken. On gelatin plates minute, slightly granular, pale-brown 

 colonies may be seen, under a low power at the end of twenty-four hours ; 

 on the sscond day these are visible as white spheres, which under the micro- 

 scope have a pale-brown color and a more or less transparent, peripheral 

 zone. In media containing glucose 110 gas is developed. The growth upon 

 agar and potato presents nothing characteristic. 



Pathogenesis. Pathogenic for Zieselmausen (Spermophilus musicus), 

 for Spermophilus guttatus, for squirrels (Sciurus vulgaris) for house mice, 

 for field mice (Arvicola arvalis). Not pathogenic for man or for the domes- 

 tic animals tested, horse, swine, sheep, fowls. Mereshkowsky proposes to 

 use cultures of this bacillus for the extermination of field mice, which die in 

 from one to ten days after being fed upon biscuit wet with a bouillon cul- 

 ture. 



169. BACILLUS OF EMMERICH AND WEIBEL. 



Obtained by Emmerich and Weibel (1894) from infected trout in ponds 

 belonging to an establishment for raising these fish. The disease appeared 

 as a superficial ' ' f urunculosis with secondary development of abscesses con- 

 taining bloody pus." Death occurred in from twelve to twenty days. The 

 pustules and secondary abscesses and blood from the heart and various or- 

 gans contained bacilli, which proved to be the cause of the infectious malady. 



Morphology. Bacilli about as long as the typhoid bacillus, but not so 

 thick, very frequently united in pairs ; occasionally grows out into filaments. 



Biological Characters. An aerobic and facultative anaerobic, lique- 

 fying, non-motile bacillus. Does not form spores. Thermal death point, 60 

 C. Stains with the usual aniline colors but not by Gram's method. Grows 

 best at 10 to 15 C. The growth in gelatin is quite characteristic. At the 

 end of two or three days, in gelatin plates, at the room temperature, small 

 white colonies are developed ; in four or five days small gas bubbles or ex- 

 cavations are seen, at the bottom of which lie the scale-like or rosetta-formed 

 colonies. The margin of the colonies is irregular and later jagged. At 

 first the colonies are grayish- white or yellowish, later brownish. The 

 superficial colonies have a peculiar lustre. In gelatin stick cultures, colo- 

 nies develop along the line of puncture, which at first resemble the growth 

 of Streptococcus pyogenes, and no development is seen on the surface. At 

 the end of five to seven days in place of the line of colonies is seen a channel 

 filled with air, or gas developed by the separate colonies, the bubbles from 

 which coalesce. The funnel formed in this way is somewhat larger above, 

 and at the bottom contains a whitish sediment consisting of bacteria con- 

 tained in a few drops of liquefied gelatin. Along the sides of the funnel 

 bubble-like cavities may frequently be seen, at the bottom of which the bac- 

 teria have accumulated. In bouillon a slight cloudiness is seen near the 

 surf ace, on the walls of the test tube; when .slightly shaken this falls to the 



