152 Veterinary Medicine. 



caemia and white scour, whereas, if the calf survived several days, 

 the impaired resistance of the tissues invited the invasion of a 

 variety of other germs from the intestines, and infective inflam- 

 mations of the lungs, joints and other organs were brought about 

 by such secondary invasions. 



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

 (Pasteurella) infection. The concentration of the morbid process 

 on the alimentary canal in acute cases strongly suggests infection 

 through the food (milk). But careful bacteriological examina- 

 tion of the milk taken with thorough antiseptic precautions from 

 the dam of a calf which had just died of white scour, and of other 

 cows in the same infected stable showed that both were free from 

 the germ. Inoculations' and culture experiments were equally 

 fruitless. 



This does not exclude the possibility of the contamination of 

 the milk, obtained under ordinary conditions, with the germ con- 

 tained in the floating barn dust, or that which was adherent to 

 the teat and udder. 



Another suggestion is that the germ is derived from the in- 

 fected womb, prior to birth, but in such a case, Nocard claims 

 that abortions would be much more prevalent, as the rapidly 

 fatal issue of the disease would determine the prompt death of 

 the foetus and its expulsion. The foetus is, however, in a meas- 

 ure protected by the absence of any infection atrium in the shape 

 of an open wound, and by the comparative absence of culture 

 media in stomach and intestines, as well as by the antiseptic 

 nature of the contents owing to the presence of biliary products. 

 Back of this is the antagonism of the maternal system which 

 would be liable to suffer first in case the cocco-bacillus were 

 propagated in the blood of the dam. The coincidence of abor- 

 tion and white scour in a herd is not uncommon, and in such cases 

 intrauterine infection of the fcetus is not improbable but in the 

 great majority of epizootics no such coincidence exists. 



We are thus thrown back on infection through the raw wound 

 of the ruptured umbilical cord, as the rule in such cases. It may 

 be that this has come from the vagina or vulva, but, in the great 

 majority of cases it is manifestly derived from the infecting bowel 

 dejections and the dust caused by their desiccation. The extra- 

 ordinarily rapid progress, and fatal result of the acute disease, 



