ANTHRAX. 271 



the blood loses its virulence, and neither rods nor 

 spores can be discovered in it after a few days. 



According to Ewart, when cultivated upon a 

 warm stage in albuminous fluids, the anthrax rods 

 become motile within a few hours, and exhibit al- 

 ternations of motion and quiescence. This does 

 not correspond with the observations of Koch, and 

 is probably a mistake. Magnin, on page 88 of the 

 present volume, in giving the specific characters 

 of B. anf /tracts, states that it is always motionless. 

 If the temperature is maintained at about 33 C. 

 (91. 4 Fahr.) the rods soon grow into long homo- 

 geneous filaments, which in the course of four or 

 five hours may reach a length many times greater 

 (50-100 times) than the original bacilli. These 

 are often twisted and interlaced in the culture- 

 fluid. A little later the filaments, which were at 

 first hyaline, are seen to consist of a distinct 

 sheath and a central cylinder of protoplasm, which 

 soon undergoes segmentation, each segment being 

 about the length of the original rods. These seg- 

 ments, and the rods themselves as found in blood, 

 break up into smaller masses under the influence 

 of staining reagents. This is seen in my photo- 

 micrograph, Fig. 1, Plate XI. The spores are 

 formed by a consolidation of the protoplasm of one 

 of these segments into an oval mass, which is sub- 

 sequently set free by rupture of the cellular en- 

 velope, or by its granular disintegration. The 

 oval shining spores after their escape present the 

 appearance of being enclosed in a gelatinous en- 



