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fever. In many cases the primary inoculation fever will 

 be constant and regular, thereafter the temperature 

 may rise and fall irregularly. In rare instances there 

 may be a low continuous fever covering 20 to 40 days. 

 Again there may occur but one fever period and that 

 occur 20 to 30 days after the inoculation. As a rule, it 

 requires from 40 to 50 days to pass through the inocula- 

 tion fever periods. After recovery from the first inocu- 

 lation, a second one is given to each animal. In case the 

 first inoculation does not produce a fever running up to 

 105, it is always best to give a second inoculation and 

 increase the dose of defibrinated blood ; if 1 cc was em- 

 ployed in the first inoculation, use 2 cc of defibrinated 

 blood in the second inoculation. As a rule, the second 

 inoculation produces fever periods as in the first inocu- 

 lation, but the fever is milder than it was following the 

 first inoculation. 



Inoculations to produce immunity to Texas fever 

 should be made in the South sometime between Nov. Ist 

 and the following March 1st, and never during hot 

 weather. During the early spring or during the winter, 

 immediately after the cattle have recovered from the 

 inoculation fever, permit a few ticks to get on them. 

 And when the hot weather of June, July, August and 

 September comes, keep off the excess of ticks by apply- 

 ing once per week over places where ticks are most fre- 

 quently found on the animals, crude Beaumont oil, or 

 a 20 per cent, kerosene oil emulsion. 



Immune animals are injured to some extent by sup- 

 porting an excessive number of ticks. 



In looking for accurate results from a large number 

 of inoculations I wrote Dr. Francis of the Texas Ex- 

 periment Station, and he kindly gave me the valuable 

 facts which you may see in his letter published below. 



