BACILLUS CHOLERA GALLINARU.M. 317 



Subcutaneous inoculation of the smallest quantity of inoculation on 

 a cultivation sets up in healthy fowls the S3 T mptoms 

 described above, and death occurs in 24 to 36 hours. 

 Pigeons, sparrows, pheasants, mice, and rabbits are 

 likewise very susceptible to the disease ; guinea-pigs, 

 sheep, and horses do not as a rule die, but abscesses 

 form at the seat of inoculation, the pus of which con- 

 tains large numbers of bacilli. Mice, fowls, and rabbits 

 can also be infected by feeding them with the cultiva- 

 tions ; dogs remain healthy even when fed for a long 

 time with the bacilli. It is probable that the natural 

 mode of infection in the poultry yards is that the dejecta 

 of the diseased animals which contain the bacilli con- 

 taminate the food, and are then swallowed by the healthy 

 animals. 



Pasteur failed to set up a fatal disease in fowls when Filtration of 

 he filtered the cultivations in neutralised chicken-broth tions. 

 through plaster or porcelain, but after large doses of the 

 filtrate there occurred in the first place a short period of 

 excitement and then moderate somnolence, which after 

 a few hours ended in recovery. This result is probably 

 to be explained by the presence of toxic products of the 

 bacilli in the filtered cultivations. Marchiafava and Celli Transference 

 have found that the bacilli of chicken cholera can pass 

 from the mother to the fostus ; such a transference is in 

 many cases a priori probable, because in chicken cholera 

 haemorrhages and lesions of the vessels occur in all the 

 organs, and in this way the organisms pass out of the 

 blood vessels. 



The bacilli of chicken cholera have excited special Attenuationo 

 interest because Pasteur carried out with them his first andproteSive 

 experiments on attenuation and protective inoculation. inoculation - 

 Pasteur observed that old cultivations which had stood 

 for several months in vessels plugged with cotton wool 

 had diminished in their virulence, as he concluded, as 

 the result of the influence of oxygen ; at any rate this 

 attenuation did not occur when he preserved the cultiva- 

 tions in sealed vessels containing only very little air. 

 The bacilli when attenuated retained the degree of 

 virulence at which they had arrived, even when further 



