RELATION OF PATHOGENIC TO SEPTIC BACTERIA. 39 



ally lengthen and then of course by their weight settle down 

 at the bottom of the fluid whence they grow upwards into the 

 characteristic long convolutions. I presume the uniform dis- 

 tribution of the bacilli and the general turbidity of the fluid 

 caused hereby in the early days is due to the bacilli following 

 Brownian molecular movement, as well as to their being able 

 to float in the fluid, but when they grow out into long threads 

 their weight and the cessation of molecular movement draws 

 them down to the bottom of the fluid, which for this reason 

 then becomes clear. That the isolated and short chains of 

 bacilli causing the general turbidity of the cultivation in the 

 first few days are really anthrax bacilli as much as the typical 

 long threads afterwards formed, is shown by the fact that if 

 with these latter a cultivation is started it presents the turbid 

 appearance in the first few days, and secondly, at any stage the 

 smallest quantity of the cultivation kills with typical anthrax 

 guinea-pigs and rabbits.^ 



With Abbe's condensor and Zeiss^ oil immersion objectives 

 it is possible to discover in these threads, already in the fresh 

 and living state from place to place, a diflferentiation of a thin 

 sheath forming the tube, as it were, and a protoplasmic con- 

 tents, and this protoplasmic contents appears subdivided into a 

 single row of short, almost cubical blocks or cells. In many 

 places this subdivision of the protoplasm into cells or even the 

 differentiation into sheath and protoplasm is not distinct in the 

 fresh state, but comes out with greater or lesser distinctness 

 after staining or after certain reagents. Thus, for instance, 

 careful staining them fresh with anilin dyes (gentian violet, 

 methyl violet, methyl blue, Spillers' purple, &c.) brings out in 

 many places this differentiation into sheath and protoplasm, 



' These peculiarities of the early bacillus growth may or may not be con- 

 nected with the ability of that growth, which is not possessed by later stages 

 of the same growth, to kill mice that are inoculated with it. However that 

 may be, these early peculiarities have no relation to spore formation. Spores 

 have, indeed, nothing in common with these rounded ends and cubical cells, 

 which stain in a way that spores do not stain, and have a quite different shape 

 and refractive power. 



