SPIRILLOSIS OF CATTLE 295 



swelling of the liver with fatty degeneration of the parenchy- 

 matous tissue. The heart muscle is sometimes affected. 

 Areas of necrosis have been described in the solid viscera. 



It is stated that the blood of the diseased fowl is not 

 infectious 48 hours after it has been removed from the fowl 

 but that if injected into a healthy fowl it will confer immunity 

 against a virulent infection. Marchoux and Salimbeni found 

 that if the fresh blood of the diseased fowl was heated for 5 

 minutes at a temperature of 55° C. it would confer immunity 

 but if it was heated for 10 minutes this property was lost. 



§ 223. Spirillosis of cattle. Theiler found .spirilla in 

 a few cattle in South Africa. The animals were suffering with 

 " red water " with possibly one exception. He sent prepara- 

 tions of these to Laveran who designated them Spirillum, 

 Theileri. Theiler made a number of inoculations with the 

 blood of animals infected with the spirilla with negative 

 results. The following description of the spirillum is quoted 

 from Theiler' s report : 



" The microorganism in question is a typical spirillum, 

 and varies considerably in its length. The longest microbes 

 measure from 20 to 30//. They are somewhat thinner at both 

 ends, otherwise the thickness is about the same throughout 

 the whole length — viz., about .25 to .\o }x. The corkscrew-like 

 forms are, as a rule, predominant, but there are other forms 

 which are atypical in appearance and also shorter. For 

 instance, the parasite may show itself as a simple curved line 

 without any spiral curves, representing sometimes the shape 

 of S ; it may also be completely doubled up, both ends may 

 meet and take the shape of a ring, or both ends may cross each 

 other and also form a loop. These loops may be of different 

 shapes and sizes. Double loops may also be found. It is 

 somewhat difficult to describe all the various forms, but they 

 can be easily imagined, considering that the spirillum is a very 

 flexible and agile parasite. 



" In preparations made by placing a cover-glass on a drop 

 of fresh blood the microorganisms are easily detected. Some 



