THE MEANING OF DISEASE 9I 



nizable, the animal goes on about his duties with 

 no apparent trouble. The disease, however, is 

 progressing all the time ; in the end it conquers its 

 victim, the final stages are reached, and the animal 

 dies. 



The stock raiser is concerned with different dis- 

 eases in so far as they mean slow or rapid recovery, 

 and particularly if they be contagious or not. His 

 entire herd will be impaired if glanders is intro- 

 duced into it. One tuberculosis cow will convey 

 the disease to all susceptible individuals in the herd 

 to which she belongs, especially if stabled in a tight 

 barn during the winter seasons when little or no 

 ventilation is intentionally provided. 



