250 



TEXAS FEVER 



Young animals were selected and injected with blood 

 taken directl_v from the jugular veins of southern animals. 

 The injections were made in the fall and winter and in the 

 spring the animals were placed in a highl}' infested field at 

 Manchester, Va. , where they remained for the summer. Dur- 

 ing this time they were under the immediate observation of 

 Dr. Cooper Curtice who made a careful study of the blood, 

 temperature and extent of tick invasion. The results of this 

 experiment are shown in Dr. Schroeder's tabulation which is 

 appended. The animals were again exposed the following 

 season without the development of Texas fever. 



The inoculation di-sease appears in from eight to ten days 

 after the injection of the blood. It lasts from one to two 

 weeks. The symptoms are occasionally of a still shorter dura- 

 tion, but the altered condition of the blood persists in some 

 cases for a much longer period. 



Dalrymple, Dodson and Morgan, of the Louisana Experi- 

 ment Station, conducted experiments along this line. To 

 show the results of their investigations, a somewhat condensed 

 summary of their experiments is given. 



Immunity against a fatal attack of Texas fever can be 

 conferred on susceptible cattle by inoculation with the blood of 



