426 BLOOD DISEASES, 



The disease in itself cannot be called contagious or infectious ;' 

 there is, therefore, no necessity for burning the carcases of 

 dead animals. 



Animals suffering from the disease, if perfectly freed from 

 ticks, do not transmit the disease, no matter how severe the' 

 attack may be ; but if invaded by the parasite, the pastures on 

 v^hich they graze are first contaminated by the mature ticks, 

 which drop from cattle, and in about seven days lay their 

 eggs in the grass; the eggs hatch in about other twenty 

 days — sometimes a longer period — and the young ticks are at 

 once ready to crawl on to the cattle. They then become again 

 encapsuled and emerge from the second shell in fourteen or fifteen 

 days. — (See p. 423). If these figures be added together, it will 

 be found that the shortest possible time, after tick-infected 

 cattle are turned out into a field, in which the disease may 

 appear is about forty days ; but the period of first attacks may 

 be much longer than this, as all the eggs are not laid upon the 

 same day : there is therefore a daily hatching for consecutive 

 days. (Own observations : Texan ticks placed in bottle on 

 5th September commenced to lay on 17th.) 



It is rather unfortunate that during the earlier part of our 

 visit the animals examined, both prior to and after death, were 

 suffering from the disease in its chronic form, and in which many 

 of the marked symptoms and post mortem conditions of acute 

 Texas fever were absent ; Imt during the latter portion of the 

 visit more decidedly marked signs of that disease were ol jserved. 



One characteristic sign of acute Texan fever (as described by 

 the American writers) — red water or blood-coloured urine, haamo- 

 globinuria — was absent. They state that " the one sign regarded 

 as peculiar and pathognomonic (characteristic) in this disease is 

 the discharge of urine having the colour of blood. This colour 

 is not due to a discharge of Ijlood from the kidneys and sub- 

 sequent breaking up of the red corpuscles, but to a filtration of 

 the colouring matter of broken-down red coi-puscles (ha:;mo- 

 globin) already in solution in the circulation, into the urine in 

 the excretory structures of the kidneys." This statement is 

 perhaps too ol^scure to be easily understood. It means that 

 the red blood-cells are broken up in the Ijlood- vessels, and that 

 the colouring matter thus set free tinges the fluid portion (which 

 is naturally colourless), and which, when excreted by the 

 kidneys, presents a red appearance. Now this sign, considered 



