LIFE HISTORY OF BACILLUS ANTHRACIS. 167 



and a small drop of aqueous humour containing ordinary 

 bacteria was added. After this the rods continued to increase 

 until they were apparently three inches in length, but as soon 

 as Bacterium tertno and other organisms introduced became 

 active all life in the filaments seemed to cease, no spores 

 appeared in them ; the filaments, in fact, became granular, 

 and soon went to pieces. 



2. In another cultivation the spores were allowed to 

 appear before any other bacteria were added ; but, although 

 thousands of micrococci were added, as well as a great number 

 of very active ordinary bacteria,. the developmental changes 

 went on unchecked, and when a mouse was inoculated with 

 the spores formed, death took place at the usual time. 



3. Pieces of spleen containing rods kept moist at a tem- 

 perature of 37° C. in free communication with the ordinary 

 atmosphere rapidly putrefied. When examined no vestige 

 of rods or filaments were found, and when pieces so ti'eated 

 were introduced under the skin of mice no symptoms of 

 splenic fever or septicsemia resulted, thus proving not only 

 that the ordinary bacteria had destroyed all the rods and 

 spores, if spores were present, oi Bacillus anthracis, but also 

 that ordinary bacteria, when introduced under the skin of a 

 healthy animal, are innocuous. 



4. Pieces of a spleen containing rods were placed in 

 aqueous humour in blood serum, in Pasteur's solution, in 

 serum from the subcutaneous tissue, and several portions were 

 sealed up in a small test-tube without any fluid being added. 

 These were kept at a temperature of 30° J. In ttie aqueous 

 humour, blood serum, and in the serum from the subcutaneous 

 tissue, the rods lengthened out into spore-bearing filaments, 

 but no changes occurred in the rods placed in Pasteur's 

 solution nor in the rods in the pieces of spleen simply sealed 

 up in the test-tube. 



5. Blood, spleen, or peritoneal fluid, containing rods or 

 spores, which at a moist temperature of 37° C. perish, may 

 be dried at a temperature of 38° to 40° C. and still retain 

 their power to set up splenic fever. The rods in the outer 

 layers of the dried masses are destroyed, but those in the 

 centre retain their activity. 



Further, rods or spores in tissues or fluids remain active 

 when sealed up in capillary tubes, and also when kept at a 

 temperature approaching freezing point. Although mice are 

 easily killed by inoculation, they do not seem to be influenced 

 in any way when rods and spores are mixed with their food, 

 unless there is some abrasion about the nose or mouth, 

 neither do they seem capable of being infected by inhaling 



