PATHOGENIC ANAEROBIC BACILLI. 



581 



This bacillus is widely distributed, being found in the superficial 

 layers of the soil, in dust, in putrefying substances, in the blood of 

 animals which have been suffocated (by invasion from the intestine), 

 in foul water, etc. 



It may usually be obtained by introducing beneath the skin of a 

 rabbit or a guinea-pig a small quantity of garden earth. The animal 

 dies within a day or two, and this bacillus is found in the bloody 

 serum effused in the subcutaneous connective tissue for a consider- 

 able distance about the point of inoculation. 



Morphology. Bacilli from 3 to 3.5 p long and 1 to 1.1 /^ broad; 



FIG. 162. Bacillus oedematis maligni, from subcutaneous connective tissue of inoculated 

 guinea-pig. X 950. (Baumgarten.) 



frequently united in pairs, or chains of three elements ; may grow 

 out into long filaments 15 to 40 /* long these are straight, or bent 

 at an angle, or more or less curved. They resemble the bacillus of 



anthrax, but are not quite as broad, have 

 rounded ends,, and in stained preparations 

 the long filaments are not segmented as is 

 the case with the anthrax bacillus. By 

 Loffler's method of staining they are seen to 

 have flagella arranged around the periphery 

 of the cells. Large, oval spores may be de- 

 veloped in the bacilli (not in the long fila- 

 ments), which are of greater diameter than 

 the rods, and produce a terminal or central 

 swelling of the same, according to the loca- 

 tion of the spore. 



Stains readily by the aniline colors usu- 

 ally employed, but is decolorized when treated by Gram's method. 



FIG. 163. -Bacillus osdema- 

 tis maligni, from an agar cul- 

 ture, showing spores. X 1,000 

 From a photomicrograph. 

 (Frankel and Pfeiffer.) 



