6^6 Veterinary Medicine. 



As the disease advances, therefore, the primary pathogenic 

 agent (the Pasteurella) is crowded out by the active growth of 

 other bacteria, which accordingly are found in complex cultures 

 and in great variety. In his first observations on the victims of 

 the white scour, Nocard found only these complex cultures, of 

 which no one variety, isolated in pure cultures in vitro, and in- 

 oculated, proved capable of causing the disease. Later he found 

 the Pasteurella (cocco-bacillus) in impure cultures from the dis- 

 eased femoro-tibial joint of one of the subjects of the affection, 

 and the pure cultures obtained from this were virulently infective. 



A few drops injected into the peritoneum of a Guinea pig, or 

 veins of a rabbit, killed in six to eighteen hours with the lesions 

 of hsemorrhagic septicaemia which characterize the most' acute 

 cases of white scour. The blood and viscera swarmtd with the 

 microbe. 



A calf one day old had 3cc. of the culture injected into the jug- 

 ular, the temperature rose in six hours, and in twenty hours the 

 subject lay with sunken eye, retracted abdomen, a temperature of 

 95° F., and having the bed saturated with a yellowish, foetid, 

 faecal liquid. Death took place 30.5 hours after the injection and 

 all the lesions of acute white scour were met with. 



A second calf four weeks old, which had already suffered from 

 white scour and recovered, had an injection into the jugular of 

 locc. of the same culture. In six hours he suffered a slight rise 

 of temperature, was dull and breathed short, but in twenty hours 

 he was completely recovered, full of life and appetite. 



In other casual and experimental cases, Nocard found that 

 when death occurred within one or two days the symptoms and 

 lesions were mainly those of haemorrhagic septicaemia and white 

 scour, whereas if the calf survived several days, the impaired re- 

 sistance of the tissues invited the invasion of a variety of other 

 germs from the intestines, and infective inflammation of the 

 lungs, joints and other organs were brought about by such sec- 

 ondary invasions. 



An important question is as to the direct source of the primary 

 (Pasteurella) infection. The concentration of the acute cases on 

 the alimentary canal would strongly suggest infection through the 

 food which in this case means the milk. But careful bacteriological 

 examination of the milk of the dam of a calf that had just died of 



