422 M. AEMAND KUFi'EE. 



leucocytes. These cells probably represent the first stage in 

 the development of macrophages ; they do not attain their full 

 size owing to the early death of the animal. On the whole, 

 macrophages play quite a secondary part at this stage. 



Many leucocytes found close to the free surface of the 

 abscess-wall contain in their interior a large number of charac- 

 teristic bacilli. Nevertheless, many micro-organisms remain 

 quite free between the cells in the surrounding medium, which 

 has been coagulated by the action of the hardening reagent ; 

 but whereas the latter micro-organisms do not show signs of 

 degeneration, many of those contained in the migrating cells 

 have undoubtedly undergone a process of disintegration. The 

 number of micro-organisms in the deeper layers of the abscess- 

 wall, at some distance from the free surface, gradually becomes 

 smaller and smaller ; and while in the upper strata some micro- 

 organisms are free between the cells, the bacilli in the lower 

 strata of the abscess-wall are always contained in the interior 

 of microphages. Lastly, a few millimetres away from the free 

 surface, although the number of migrating cells is still very 

 large, no bacilli are to be seen except occasionally the remnant 

 of a dead micro-organism contained in an amoeboid cell. 



It will be convenient to speak now of the forms of degenera- 

 tion as seen in the micro-organisms of quarter-evil, when they 

 have been taken into the interior of lymphocytes. I will 

 describe these changes as seen in preparations examined with 

 a Verick microscope, oil immersion xj^^ ^^' tV^^^ ocular 1 or 3, 

 and Abbess condenser. The bacilli not contained in the cells 

 I shall, for brevity's sake, call extra-cellular micro-organisms, 

 whilst the bacilli in the interior of leucocytes must go by the 

 name of intra-cellular micro-organisms. 



The extra-cellular micro-organisms present in the coagulated 

 exuded fluid, when carefully examined, consist of rods some- 

 what shorter and thicker than anthrax bacilli. Spores are not 

 often present when the virus is inoculated into guinea-pigs. 

 The bacilli stain of a deep blue colour with methyl-blue, in- 

 tensely red with fuchsin, and purple with gentian-violet. 



Though staining uniformly, the extra-cellular bacilli are not 



