342 AGRICULTURAL BACTERIOLOGY. 



spores must be regarded as among the most resistant of all 

 known forms of living matter. When dried the spores may 

 remain alive for a long time, many years at least, and yet all 

 the time retain their power of developing when placed under 

 proper conditions. All of these facts are of the greatest im- 

 portance in enabling us to understand the phenomena con- 

 nected with the disease, and they evidently make the disinfec- 

 tion of an infested locality a matter of very great difficulty. 



Although this disease is extremely fatal, animals affected 

 rarely recovering, it is not particularly contagious, and is rarely 

 communicated directly from animal to animal. One common 

 method by which cattle are infected appears to be through the 

 food which they crop in the fields. It has often been noticed 

 that the disease breaks out in a herd shortly after it has been 

 turned into a new pasture. In some of these cases which 

 have been investigated the explanation of the infection is a 

 simple one. In such pastures the dead bodies of animals 

 dying from anthrax have been buried in earlier years. The 

 bacilli of course die quickly, but the spores may remain alive 

 for many years. Now, although these spores may have been 

 buried some distance below the surface, it is certain that they 

 are eventually brought to the surface. One of the means by 

 which they are brought up from under ground is through the 

 agency of earthworms. Earthworms are constantly taking 

 earth into their bodies and voiding it at the openings of their 

 burrows at the surface of the ground. In this way they are 

 continually bringing soil from some depth to the surface, and 

 it is easy to suppose that they may thus bring up the anthrax- 

 spores. This suggestion, at first tentatively advanced and 

 much doubted, has, in later years, been demonstrated by find- 

 ing the anthrax bacillus in the bodies of earthworms which 

 were taken from pastures where the bodies of anthrax animals 

 had been buried. The spores thus brought to the surface may 

 certainly infect animals feeding on the grass. This too has 



