284 BACTERIA. 



ground is usually below 12° C, so that animals piit below 

 this depth, even if swarming with bacilli, cannot be 

 looked upon as centres of infection ; the organisms, no 

 longer able to form spores, soon lose their virulence and 

 die out altogether. In order to get rid of any spore- 

 bearing bacilli, all discharges or blood that may have 

 escaped at the place where the animal lay after death 

 should be carefully disinfected with 5 per cent, carbolic acid. 

 It was for long thought that by cultivating the anthrax 

 bacillus through a great number of generations on ordinary 

 nutrient media it could gradually be converted into the 

 hay bacillus or the bacillus subtilis — a very similar 

 organism, but one that has no pathogenic properties — and 

 Buchner, in a published series of experiments, claimed that 

 he had obtained this conversion, and that in the same way 

 he could again turn back the wheel from the hay bacillus to 

 the pathogenic form. These results, however, fiave not been 

 repeated, although many have tried similar experiments ; 

 but Hueppe and Wopd, by using a species of earth bacillus, 

 which, in its morphological characters and method of growth 

 on nutrient media, appears to be almost identical with 

 anthrax bacillus (but possesses no pathogenic properties), 

 have found that it must be very nearly related phylogene- 

 tically, from the fact that when inoculated into animals it 

 acts as a kind of vaccine, and renders the animal immune to 

 an attack of anthrax. 



It will be well, however, to take up this and other ques- 

 tions relating to anthrax in connection with vaccination and 

 immunity. 



Literature. 



The following works may be consulted : 

 Bollinger. — Centralbl. f. d. Med. Wiss., No. 27, p. 417, 



1872. 

 Brauell. — Virch. Arch., Bd. xl, Heft. 2, p. 121, 1857, and 



Bd. XIV., Heft. S, 6, p. 432, 1858. 

 Buchner. — Nageli's Untersuch. u Nied. Pilze ; Eine neue 



Theorie u. Erziel d. Immunitat gegen Infectjonskran- 



kheiten Munchen, 1883 ; Virch. Arch., Bd. xci.. Heft. 



3, p. 410, 1883. 

 Chauveau. — Comptes rendus. 1880-1885. 

 Davaine. — Comptes rendus, 1 863-1 866. 



