19 4 ANTHRAX. 



temperatures, regaining its activity after remaining at — 40° C. 

 for long periods, on being placed in conditions suitable. 



Life History of Bacillus Anthracis. — That we may more 

 readily comprehend the recent and generally received view of 

 the pathology of anthrax we will here briefly glance at a few 

 of the principal facts in the life-history of bacillus anthracis, 

 and its artificial cultivation in relation to protective inocula- 

 tion, and some arguments in favour of the adoption of the 

 theory that this bacterium and anthrax stand in relation to 

 each other as cause to effect — indeed, that the organism is a 

 true ''pathophyte.' 



After much debate as to whether vegetable or animal king- 

 dom should rightly claim among its orders the little living 

 particle under consideration, I believe it is now unanimously 

 allotted a place in the former, botanists putting it among 

 the ' schizomycetes ' (literally, fungi which split up), with 

 which the term ' bacteria ' is used interchangeably. Biologists 

 have variously arranged these ' protean organisms ;' but this 

 part of the subject is not within our province, so we content 

 ourselves with saying bacillus anthracis, the bacteridium of 

 Davaine, is a rodlike body of the bacteria class. It consists of 

 elongated cylindrical rods, homogeneous or almost granular 

 in appearance, which multiply by transverse fission. Sometimes 

 forming long chains by union of these rods, at the junction of 

 which there are no constrictions, they curve in various direc- 

 tions, and the mass may assume different forms. These bodies 

 have periods of rest and motion. Spore-production goes on in 

 these filaments, which are seen as round or oval bodies, highly 

 refractile, on the sides or ends of the rods, enclosed within a 

 soft membrane which ruptures and allows their escape, which 

 may take place singly or in masses or swarms ; or the sheath of 

 the filament may persist, enclosing a number of spores. The 

 spores may again undergo division, generally into fours. They 

 do not always form into rods. The rods developed from the 

 spores are said to increase their length 120 times in twenty- 

 four hours, and in forty-eight hours to present a dotted ap- 

 pearance — spore-production. This process is most active at 

 from 24° C. to 28° C. An idea of the rapidity of development 

 of the bacillus anthracis can best be conveyed by narrating 

 the following experiment : The TryVrrt-h oi a cubic millimetre 



