470 PATHOGENIC AEROBIC BACILLI 



" Potato : Bright-yellow, glistening, moist surface with well-defined bor- 

 ders, and but slightly raised above the siirrounding potato. 



" Action on Milk and Litmus Reaction. Milk is coagulated into a solid 

 clot in twenty-four hours at 38 C. Milk colored blue with litmus is changed 

 to pink in twenty-four hours at 38 C. , and in forty-eight hours is reduced to 

 white or cream color with a thin pink layer on top. 



" Gas Production. Gas bubbles arise in milk cultures, but they have not 

 been observed on potato cultures. 



" Temperature. Grows better at 38 C. 



'* Spores have not been observed. 



"Relation to Gelatin. Does not liquefy gelatin. 



"Resemblance. It closely resembles Bacterium coli commune and Brie- 

 ger's bacillus in the character of its growth upon different media, but is readily- 

 distinguished from both, as is also Brieger's bacillus from the Bacterium coli 

 commune, by the following differential test recently made known by Dr. 

 Mall. Yellow elastic tissue from the ligamentum nuchae of an ox is cut into 

 fine bits and placed in test tubes containing water with ten-per-cent bouillon 

 and one-per-cent sugar, and sterilized from one and one-half to two 

 hours at a time for three consecutive days. Into this is inoculated two 

 species of bacteria, one of which is the bacterium under observation, 

 the other a bacillus found in garden earth. The latter bacillus is anaerobic, 

 grows in hydrogen, nitrogen, and ordinary illuminating gas, in the bottom 

 of bouillon, in the depth but not on the surface of agar stab cultures, and 

 not at all in gelatin stab cultures. It has a spore in one end making a knob 

 bacillus. Different species of bacteria Streptococcus Indicus, tetragenus, 

 cholera, swine plague, Bacterium lactis aerogenes, Bacterium coli commune, 

 Brieger's bacillus, and a number of varieties of bacteria which I have iso- 

 lated from the faeces were inoculated with the head bacillus into the above- 

 described elastic- tissue tubes. The tubes inoculated with Brieger's bacillus 

 developed a beautiful purple tint, which started as a narrow ring at the top 

 of the culture, gradually extending downward and deepening in color until 

 the whole tube had a dark-purple color. This color reaction began in five to 

 fourteen days, and was constantly present in a large number of tests. Tubes 

 inoculated with bacillus / gave a much fainter purple color, which was 

 longer in appearing and never became so dark as with Brieger's bacillus. 



"Tubes inoculated with the other species of bacteria above mentioned gave 

 no color change and remained similar to control. Bacillus / also shows a 

 slight difference from Bacterium coli commune in coagulating milk and re- 

 ducing litmus more rapidly, and appears to produce moreactive fermentation 

 in milk. Like Brieger's bacillus, the gelatin colonies more frequently show 

 a concentric arrangement than those of the Bacterium coli commune," 



BACILLUS g OF BOOKER. 



" Found in one case of serious gastro-enteric catarrh. It was not in large 

 quantity. 



' Morphology and Biological Characters. In morphology, character of 

 growth on agar, gelatin, and potato, it resembles Bacterium coli commune. 



" Action on Milk and Litmus Reaction. Milk is not coagulated, and milk 

 colored blue with litmus is changed to pink in a few days, and holds this 

 color. These characteristics distinguish it from the Bacterium coli com- 

 mune. 



" Gas Production. Not observed in milk or potato cultures. 



" AWf/f/oH t<> Crltttin. Dors not liquefy gelatin.' 1 



