5 Anthrax. 



may sometimes be infected by subcutaneous injections and by 

 feeding (Perroncito, Crookshank, G-arth), yet in most instances 

 they resist artificial infection (Eatz, Tscliernogoroff). Dogs oc- 

 casionally become ill from intravenous injections with pure cul- 

 tures (Bardach, Martel), and exceptionally from the feeding of 

 anthrax meat. Plowever, as a rule they manifest considerable 

 resistance to artificial infections. Young pigeons _ and small 

 birds in general may be quite easily infected artificially, while 

 in large birds as well as in chickens infection is difficult. 



The high virulence of the blood of animals dead of anthrax 

 has been established by experiments, according to which a mil- 

 lionth part of a drop of blood injected subcutaneously kills a 

 guinea pig in 23-24 hours (Davaine). By repeated passage 

 of the virus through the body of susceptible animals (mice, 

 guinea pigs) as well as through resistant animals (chickens, 



Fig. 5. Spore formation in anthrax 



hacilK. Eight-hours old agar 



culture stained with diluted 



fuchsin solution. 



Fig. 6. Anthrax threads with spores. 



Cover glass preparation from an 



i eight-hours old agar culture. 



Fuchsin staining. 



dogs) its virulence is increased, and in this manner a virus 

 which is fatal in 24-30 hours may be obtained (Martel). On 

 the other hand, influences which check the development (high 

 temperature, disinfectants as well as the continuous action 

 of the oxygen of the air), have attenuating effects on both the 

 bacilli and the spores. (See protective immunization.) 



In the presence of certain other bacteria the multiplication of the 

 ■anthrax bacillus is hindered or entirely cheeked. As such antagonists 

 the following are known: Bae. pyocyaneus, prodigiosus, fluorescens, 

 phosphorescens, Gartner's bacillus, Friedlander 's pneumococcus, 

 streptococci and staphylococci, and the anserobic putrefactive bacteria. 

 The antagonism manifests itself in such a way that virulent anthrax 

 bacilli when mixed with such antagonists have little or no pathogenic 

 action. 



The natural infection in herbivorous animals occurs usually 

 through the ingestion of food and water which contain anthrax 



