STUDY OF THE BACILLUS OF ANTHRAX. 233 



to 1.25 p. Frequently very long threads made up of 

 several rods, joined end to end, are seen. 



As it is obtained from the body of the animal, it is 

 usually in the form of short rods square at the ends. 



When cultivated artificially at the temperature of the 

 body, the bacillus of anthrax presents a series of very 

 interesting stages. 



The short rods develop into long threads, which may 

 be seen twisted or plaited together after the manner of 

 ropes, each thread being marked by the points of junc- 

 tion of the short rods composing it. 



In this condition it remains until alterations in its 

 surroundings, most conspicuously diminution in its nutri- 

 tive supply, favor the production of spores. When this 

 stage begins, alterations in the protoplasm of the bacilli 

 may be noticed; they become marked by irregular, gran- 

 ular bodies, which eventually coalesce into glistening, 

 oval spores, one of which lies in nearly every segment 

 of the long thread, and gives to the thread the appear- 

 ance of a string of glistening beads. In this stage they 

 remain but a short time. The chains of spores, which 

 are held together by the remains of the cells in which 

 they formed, become broken up, and eventually nothing 

 but free oval spores, and here and there the remains of 

 mature bacilli which have undergone degenerative 

 changes, can be found. In this condition the spores, 

 capable of resisting deleterious influences, remain and, 

 unless their surroundings are altered, have been seen to 

 continue in this living, though inactive, condition for a 

 very long time. When placed under favorable condi- 

 tions again, each spore will germinate into a mature cell, 

 and the same series of changes will be repeated until 

 the favorable surroundings become again gradually 



