340 VETERINARY BACTERIOLOGY 



atures. The thermal death-point for non-sporulating rods is 

 55 for five minutes, and for the sporulating rods, 100 for fifteen 

 minutes. The organism is aerobic. Neither gas nor acids are 

 produced from carbohydrates. Gelatinase is produced, but 

 not enzymes that will proteolize milk or blood-serum. 



Pathogenesis. Experimental Evidence. The proof that this 

 organism stands in an etiologic relation to the disease does not 

 seem to be entirely satisfactory. An organism not distinguishable 

 from this has been isolated from soil, dung, and hay in localities 

 from which the disease has not been reported. Intraperitoneal 

 injection of the heart blood from a case of trembles into a rabbit 

 resulted in death, and the organism was recovered from various 

 internal organs. Subsequent efforts at infection with pure cul- 

 tures failed. Inoculations into the guinea-pig were unsuccessful. 

 Feeding experiments upon dogs and cats were more successful, 

 and a disease corresponding to milk sickness was produced when the 

 organisms were fed in large quantities. 



Character of Disease and Lesions. Jordan and Harris give the 

 following characterization of the disease. " The course of the 

 disease in cattle is marked by lassitude and muscular weakness, 

 sometimes, but not invariably, accompanied by constipation. 

 There is often muscular twitching or trembling, and occasionally 

 signs of nervous excitement. In man there is, as a rule, excessive 

 vomiting, and obstinate constipation accompanied by great weak- 

 ness. The temperature is normal or subnormal." In cattle, the 

 principal lesion observed is fatty degeneration of the liver. Ecchy- 

 moses in the heart- wall, the liver, and spleen have been noted. 



Immunity. Experiments relative to the agglutinating power of 

 serum have not yielded consistent results. Nothing is known of 

 methods of conferring immunity. 



Bacteriologic Diagnosis. The organism may be isolated in pure 

 culture from the infected organs and may be identified by its char- 

 acteristic morphology. 



