244 



ANTHRAX BACILLUS 



FIG. 132 



2. Mix 1 or 2 c.c. of this emulsion with an equal amount of Ziehl's 

 carbol fuchsin and place in a watch-glass or small beaker. 



3. Heat over a small flame for about six minutes, until vapor rises. 



4. Spread some of the mixture upon a cover-glass or slide, allow the 

 preparation to become air dry, and fix by drawing twice through a flame. 



5. Decolorize for one or two seconds in 1 per cent, sulphuric acid 

 watery solution; wash in water, counterstain in watery methylene 

 blue for three or four minutes. 



As a result of the stain the spores show red and the bacilli blue. 

 The best culture medium for the production of an abundant spore 



formation is boiled sterilized 

 potato, cut into halves or disks, 

 and kept at temperatures be- 

 tween 31 and 37 C. Another 

 excellent method for obtaining 

 abundant sporulation consists in 

 pouring bouillon containing 

 anthrax bacilli on agar plates. 

 When spore formation is studied 

 directly under the microscope 

 the following changes are seen. 

 There first occurs a clouding 

 of the previously clear proto- 

 plasm of the bacillus, the latter 

 forming fine granules and ap- 

 pearing as if it had been dusted. 

 Then larger, highly refractive 

 granules appear, and these, 

 probably by uniting with each 

 other and with other substances of the bacillus, form the round or 

 slightly oval spore. 



Germination of Spores. Spores or sporulating bacilli under favor- 

 able conditions, either in nature, in the body of a susceptible animal, 

 or in a suitable culture medium, develop again into young bacilli. 

 The tough spore membrane swells up and becomes elongated, the 

 spore itself within the -membrane loses its shining refractive appear- 

 ance, and a hole or rupture appears in the membrane through which 

 the elongated spore, having now assumed the shape of a young bacillus, 

 makes its exit. Occasionally a short bacillus with a round, empty 

 capsule at one end is seen in preparations from anthrax cultures, 

 giving the appearance of a bacillus with a spore at one pole, such as 

 is found in the case of the sporulating tetanus bacillus. With the 

 anthrax bacillus, however, this appearance is deceptive and in reality 

 only indicates a young bacillus and an empty spore membrane or 

 capsule at one end. Germination of spores, after they have been 

 brought into a favorable culture medium, and if kept at temperatures 

 between 30 and 37 C., begins generally after eight hours. 



Anthrax bacillus, spore formation X 1000. 

 (Author's preparation.) 



