380 



TIMOTHY RICHARDS LEWIS. 



Cohn's paper, will be found on another page (fig. 13). The 

 rods of the ])ig-bacUliis (fig. 10) are referred to as being thinner 

 than those described by Cohn as occurring in hay solutions, also 

 thinner than those of the Bacillus ant/iracis, and, unlike the 

 latter (according to Davaine, Pasteur, Koch, and others), 

 possess a moving stage.^ It will, however, be recollected that 

 Dr. Ewart has shown that Bacillus anthracis may also 

 manifest very active movements. Under favorable circumstances 

 the filaments grow into leptothrix-like filaments (fig. 12) just as 

 other bacilli are known to do. 



Fig. 10. 



Fig. 11. 



Fig. 12. 



Fig. 10. — The Bacillus of infectious Pneumo-enteritis of the pig, cultivated 

 in aqueous humour of rabbit, showing spores germinating into rods, 

 isolated rods, and series of rods. 



Fig. 11. — From a similar specimen, as in fig. 10, at a later stage ; most of 

 the rods have grown into long fdaments. 



Fig. 12. — Showing the formation of bright cylindrical spores in the fila- 

 ments at a later stage. 



The drawings are represented as the objects appear when seen 

 under a Zeiss's F objective, and Hartnack's III eye-piece, fitted to a 

 Hartnack's small stand (after Klein). 



" In these filaments," writes Dr. Klein, " highly refractive 

 spores make their appearance (fig. 12). These become free after 

 the disintegration of the original filamentous matrix. The fully 

 developed spores of our bacillus difi'er from those of hay-bacillus 

 and anthrax bacillus by being more distinctly cylindrical and 

 much smaller.^^ In a footnote it is mentioned that in the figures 

 accompanying Koch's first paper in Cohn's ' Beitrage ' (1876) 

 *'the spores are represented in many places as more or less 



1 The letters a, b, used in the original figures (as given in the ' Micro- 

 scopical Journal '), appear to have become accidentally transposed by the 

 lithographer, as wliat is referred to in tlie text under " A, Bacillus of infec- 

 tious Pneumo-enteritis of the pig, cultivated in aqueous humour, showing 

 spores germinating into rods, isolated rods, and series of rods," evidently 

 refers to B in the plate, and not to the figure marked A. 



