268 AGRICULTURAL BACTERIOLOGY 



them chemically to such an extent that they are unable 

 to stimulate the vaccinated animal to produce bodies 

 that protect from a natural attack. The term "bac- 

 terine" is applied to killed cultures of bacteria used for 

 protective purposes. The vaccine used to protect against 

 typhoid fever is of this nature. The value of the vaccine 

 in preventing hemorrhagic septicemia is not fully estab- 

 lished. In small herds the isolation of the healthy animals 

 from those that show any symptoms is preferable to vac- 

 cination. The healthy animals should be removed to a 

 fresh pasture or meadow and staked out so that no contact 

 between the animals can take place. The carcasses should 

 be disposed of with the same care as in the case of anthrax. 

 If animals die in the stable, the litter should be burned, 

 the stable cleaned and disinfected. The organisms are 

 easily destroyed, since they do not form spores; conse- 

 quently there is no danger that they will persist in yards 

 and stables, as in the case of anthrax. 



Corn-stalk disease. In those sections of the country in 

 which it is the custom to harvest the ear corn in the row, 

 and then turn the stock into the standing fodder, a disease 

 known as corn-stalk disease is sometimes encountered. The 

 trouble appears soon after the cattle or horses are turned 

 into the field (four to ten days) and runs a rapid course. 



On account of the suddenness with which death occurs, 

 and the large losses that follow in a short time, it is often 

 mistaken for a contagious disease, especially for anthrax, 

 blackleg, or hemorrhagic septicemia. It is important, how- 

 ever, to differentiate the trouble, which is probably phys- 

 iological, from those diseases that are caused by specific 

 organisms. The differentiation can be made by the lack 

 of abnormal changes in the tissues, and the relation of the 

 appearance of the disease to the period of admission of the 

 animals to the fields. 



