ANTHRAX. 283 



and slightly concave, and when united the concave ends enclose 

 a lenticular space ; they are non-motile, and their ends are not 

 rounded but terminate sharply. 



According to the observations of Koch, it appears that, what- 

 ever be the species of animal inoculated with anthrax blood, 

 and no matter how many successive inoculations may be made, 

 the lacilli multiply solely by fission, but only so long as the 

 animal is alive ; when dead a minute portion of its blood, placed 

 in aqueous humor, and kept at a temperature of 35° to 37° C. 

 (95° to 98f ° F.), the rods, as already stated, lengthen out very 

 considerably. This process of lengthening of the rods into 

 filaments is apparently effected by the temperature. In five 

 hours a rod at a temperature of 32° C. (89-6° F.) may have 

 increased so as to be from eighty to one hundred times its 

 original length, and in twenty-four hours the filament may 

 be full of spores. If the temperature, however, be kept about 

 28° C. (82"5° F.), the spores may not appear till the thirty-sixth 

 or fortieth hour. When the spores have once appeared, all the 

 other changes go on at ordinary temperatures from 12° C. 

 (53-6° F.) to 18° C. (64-4° F.), but not nearly so rapidly, even 

 when the preparation is kept in the sun for a few hours daily, 

 as when artificial heat is applied. On the other hand, a high 

 temperature, 37° to 40° C. (98-6° to 104° F.), at once checks all 

 developmental changes. 



The filaments differ in cultivated specimens very much in 

 their arrangements. Sometimes they form a network — indeed 

 a mycelium — made up of numerous, nearly parallel, unbranohed 

 threads, crossing each other at different levels ; the threads are 

 sometimes straight, but have generally a wavy outline. This 

 condition may obtain throughout the whole preparation, but 

 generally at some parts the filaments are extremely irregular 

 and much convoluted. 



Pasteur stated that the spores of bacilli remained toxic after 

 boiling ; and after being subjected to a pressure of twelve atmo- 

 spheres of oxygen. Dr. Burden Sanderson and Dr. Cossar Ewart 

 tested the accuracy of this statement, and found that mice 

 inoculated with the boiled and compressed solutions remained 

 quite well. 



The experiments of Bert, however, support to some extent 



