PART III.] 



Development of Spores of Bacillus Anthracis. 



575 



The latest contribution which has been made towards this inquiry is from the 

 pen of Dr. J. Cossar Ewart.* Dr. Ewart confirms Dr. Koch's experiments in many 

 points, and his description of the development of the rods into filaments [Fig. 43, and 

 Fig. 44, (a) ] corresponds with that of previous writers ; but his description and figures 

 of the germination of the " spores " are totally different. " The spores," writes Dr. Ewart, 

 " when free, according to previous observers, at once grow into rods, and, according 

 to Koch at least, the rod is formed out of a gelatinous-looking envelope surrounding 

 the spore. My observations lead me to believe that the spore does not always at 

 once grow into a rod, but that it divides into four sporules by a process of division, 



Fig. 4.S. — Baelllus (mthracin : Kocls undergoing 

 segmentation and lengthening into a 

 filament. (After Ewart.) x?diara. 



Fig. 44. — Bacillus anthracu : (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 

 different stages through which a spore 

 passes in its development into a rod, (After 

 Ewart.) X ? diam. 



©> 



Fig. 45. — Bacillus antliraeis : A sporule 

 developing into a rod. (After Ewart.) x ? diam. 



in which the envelope as well as the spore takes part. This division I have seen 

 beginning before the spore escaped from the filament [Fig. 44, b], and that it is not a 

 degeneration is certain, for I have watched the sporules thus formed lengthen into rods 

 [Fig, 44, (c)]. Dr. Koch states that the rods are developed from the gelatinous-looking 

 capsule, and not from the bright, shining spore. From what I have seen I think there 

 can be no doubt whatever that the capsule takes no active part during the formation 

 of the rod. The sporule thus slightly elongates [Fig. 45], and then from one of its 

 poles an opaque process appears, which, as it slowly lengthens, pushes the capsule 

 before it, as it would an elastic membrane. The capsule, as this stretching goes on, 



* Q^iarterly Journal of Microscopical Science, April 1878, p. 161. 



