lin-< Kkport S.A.xV. Advanckmext of Sciknck. 



cases, the first maximum l^eing readied about the ele\enth or twelfth 

 day after inoculation, the second rise occurring about the twenty-fifth 

 day, the temperature subsecjuently subsiding to normal, while the 

 second inoculation was succeeded by a febrile reaction of the same type, 

 but of a less severe character. 



These misleading results, we now know, followed because the 

 blood used foi" purposes of inoculation was taken from animals im- 

 mune to Texas fever and from animals suftering from a mixed infection 

 of East Coast fever and ordinary Texas fever, cases of a class which 

 are such a constant feature in outbreaks of the former disease in a 

 country in which Texas fever is endemic, our inoculated animals re- 

 sponding to the infection of Texas fever, which is inoculable, and being 

 unaffectetl b}' East Coast fever, which is uninoculable. 



Later inoculation experiments with blood taken from acute cases 

 carried out upon adult cattle salted to Texas fever, and coming from the 

 coastal districts of Natal, were also accompanied by febrile reactions 

 about eighteen days later, which terminated fatally. These reactions 

 we believed at the time were the result of the inoculation to which the 

 animals were subjected, but there is of course now no doubt that the 

 illness in these cases was the result of allowing the animals to run on 

 veld which had by this time become tick infected, although we Avere 

 not at that time unaware of the fact. While these experiments were 

 going on no opportunities were lost of making post mortem examina- 

 tions of animals dying of the disease. As the mortality was extreme 

 the number of animals examined was very considerable, and although 

 I have had manv opportunities since that time of making examina- 

 tions of animals which had fallen victims to East Coast fe\er, 1 have 

 never come across cases in which the symptoms presented during 

 life and the lesions found after death were more severe than they 

 were in cattle then dying on the .Salisbury commonage, which more 

 closely resembled Hstr-morrhagic Hepticjt'mia than that of any disease 

 known to science. All cases, however, did not present symptoms of a 

 similar character, nor were the post mortem appearances in\ariably 

 tlie same, and at this time we divided them into two classes, which we 

 designated as typical and atypical, the cases record(Hl in the typical 

 class being those presenting the ordinary symptoms and post mortem 

 appearances generally seen in the course of ordinar}' outbreaks of Texas 

 fever, and those relegated to the atypical class being those animals in 

 which the symptoms and post mortem appearances deviated from the 

 normal t3^pe and w hich were peculiar to the present outbreak. 



Here a little space may be devoted to the description of what 

 were looked upon as typical and atypical forms of the disease. In 

 the former the affected animal after an interval of two or three days, 

 in which the only evidence of systemic disturbance was an elevation 

 of temj)eratur(' in many cases rising to lOtV F. or 107 F., presented 

 the following appearances, which \ may (piote herewith from a rejiort 

 publisluHl at the time by Mr. llobertson and myself :- 



"The animal is dull and the appetite capricious, although the act 

 (>f tumination may be performed at intervals; in milch cattle there is 



