434 :^r. aemand buffer. 



The macrophages filled with bacilli and cells, swollen in 

 consequence of the formation of large vacuoles, finally burst 

 and allow their contents to escape. The bacilli, freed in this 

 way, often show signs of degeneration. Thus one meets with 

 free bacilli, segments of which stain violet and pink alternately. 



Confirmatory evidence has been obtained by MetschnikoflF 

 by studying the processes taking place when pigeons are 

 inoculated with anthrax. This animal is immune against the 

 disease, and Baumgarten^ and Czaplewski state that anthrax 

 bacilli introduced under the skin of pigeons perish sponta- 

 neously at the end of four hours, the phagocytes taking no part 

 in their destruction. Lubarsch also came to the same conclusion. 



Nuttall, on the other hand, thought that the blood of 

 pigeons is a medium in which the bacilli of anthrax begin to 

 grow almost immediately after their introduction into it. 



MetschnikoflF" then proved that anthrax does not become 

 attenuated in pigeons, but often acquires new virulence. 



The aqueous humour of pigeons introduced into capillary 

 tubes and inoculated with spores of anthrax proves a most 

 satisfactory cultivating medium, the spores giving rise to an 

 abundant crop of felted threads, which are perfectly normal 

 iu appearance and ultimately produce innumerable spores. 

 The same result is obtained when anthrax is inoculated into 

 the aqueous humour of the eye of a pigeon which has been 

 rendered doubly immune by a previous inoculation of anthrax 

 from which it has recovered. 



The same result can be obtained by inoculating the exudation 

 fluid with an exceedingly small quantity of an old culture of 

 the first vaccin of anthrax. The day after the inoculation the 

 whole drop is full of an abundant culture of normal anthrax 

 filaments. 



The following experiment is extremely interesting : — A small 

 piece of silk thread loaded with spores was introduced into the 

 anterior chamber of the eye of an immune pigeon inoculated 



> ' Ceutralblatt fur klinisclic Mediciu,' 1888, No. 29, p. 516. 

 2 Metschnikoff, " I^tudes sur I'lmmunit^ : Le Cbarbon des Pigeons," 

 ' Annales de I'lnstitut Pasteur,' 3 890, vol. iv, p. 65. 



