TEXAS FEVER. 149 



lated. This will produce tick fever in from seven to ten days. 

 From this not more than one to three per cent will die if the 

 subjects have been selected with proper care and are judiciously 

 handled. 



Important conditions. — The animals should be between nine 

 and fifteen months old. 



The inoculating should be done during December, January or 

 February, for tick fever is less severe in cold weather. 



All ticks should be kept off the inoculated cattle until they 

 have fully recovered from the inoculation fever. 



The inoculated cattle should at first be protected from gross 

 tick infestation by having their legs and under parts of their 

 bodies greased. 



The inoculated animal should be infested with the first crop 

 of ticks appearing in the spring, for these are probably less viru- 

 lent than those hatched in the fall, and therefore, produce a type 

 of disease intermediate in severity between the inoculation fever 

 and that caused by the fall ticks. 



If these precautions are taken not more than three to five 

 per cent will die from tick infestation after inoculation. 



In the opinion of the writer the best method of introducing 

 pure bred animals for improvement of the native stock is to im- 

 port calves under four months old and allow them to become 

 immunized by tick infestation as occurs with our native born 

 stock. 



