370 TIMOTHY RICHARDS LEWIS. 



germinating process. The foregoing, according to various writers, 

 represents the complete cycle of development undergone by 

 Bacilhis anihracis. 



Davaine, it will be recollected, had found that animals eating 

 diseased tissues mixed up with their food became themselves 

 affected, and he believed that the spread of the disease could 

 thus to some extent be easily accounted for. Koch, on the con- 

 trary, finds that animals very susceptible to infection by inocu- 

 lation, such as mice and rabbits, may devour such a mixture with 

 impunity. Attempts to inoculate two dogs, a partridge, and a 

 sp'arrow, proved fruitless. 



The latest contribution which has been made towards this in- 

 quiry is from the pen of Dr. J. Cossar Ewart.^ Dr. Ewart 

 confirms Dr. Koch's experiments in many points, and his descrip- 

 tion of the development of the rods into filaments [fig. 7, and 



Fig. 7. — Bacillus anthracis : Rods undergoing segmentation and lengthen- 

 ing into a filament (after Ewart). x ? diam. 



fig. 8 (a)] corresponds with that of previous writers ; but his 

 description and figures of the germination of the ' spores ' are 



o ® (So) ©o gm 



Fig. 8. — Bacillus anthracis : (a) A filament containing spores, becoming 

 granular at one end, and showing transverse lines between the spores ; 

 (b) part of a filament containing a spore in process of division ; (c) 

 shows the difi'erent stages through which a spore passes in its develop- 

 ment into a rod (after Ewart). x ? diam. 



totally different. "The spores," writes Dr. Ewart, " when free, 

 according to previous observers, at once grow into rods, and, 

 according to Dr. Koch at least, the rod is formed out of a gela- 

 tinous-looking envelope surrounding the spore. My observations 



^ ' Quarterly Journal of Microscopical Science,' April, 1878, p. 161. 



