46 DR. E. KLEIN. 



without spores, and their protoplasm crumbles down into a 

 granular debris. Under all conditions, however, the thread 

 becomes much thicker, the sheath swells up, and gradually is 

 lost as such. In some cell specimens I noticed an abortive 

 formation of spores ; these appeared as irregularly distributed 

 spherical small spores, which never grew into the typical fully- 

 formed large elongated spores. 



The conclusion we then arrive at from all these observations 

 is this : — Under most favorable conditions every elementary 

 cell is capable of forming a spore ; these spores are bright and 

 glistening, and do not stain (see Koch). At first they are 

 spherical, afterwards larger and oblong. If the cell is an ele- 

 mentary or cubical one it forms one spore ; if it is elongated 

 and constricted, i. e. before dividing, it may form two spores 

 not all the protoplasm of the cell is involved in the formation 

 of the spore, a trace of it is left around the spore, but sooner or 

 later crumbles away as a granular debris. If the conditions 

 are not so favorable only a limited number of cells form spores, 

 in the rest the protoplasm degenerates into granular debris, 

 and under unfavorable conditions, especially in the absence of 

 a sufficient supply of air no spore is formed in any of the cells. 

 When spores are formed they escape after the sheath breaks 

 down. 



Ewart (1. c.) maintains to have observed a division of the 

 spores after they had become freed of the bacillus sheath. 

 This statement also requires confirmation. The above-men- 

 tioned couples of spherical spores Ewart also noticed, but they 

 are not due to a division of spores as Ewart maintains, but are 

 developed as such in an oblong dividing cell. 



I now enter one of the most important parts of this research, 

 viz. the results of the inoculation of rodent animals with 

 the Bacillus anthracis of the artificial cultivations described 

 above. 



At the outset I wish to state the manner in which the inocu- 

 lations were carried out. The animals used were Avhite and 

 tame brown mice and offsprings of both ; further, guinea-pigs 



