772 MICROBIOLOGY OF DISEASES OF MAN AND DOMESTIC ANIMALS 



agglutination and complement deviation tests and by the fact that it 

 can be gradually adapted to ordinary media. 



The production of pertussis in young animals has been claimed. > 

 The organism has an endotoxin which produces local necrosis after 

 subcutaneous injection. 



Further evidence on the etiology of whooping cough is afforded 

 by the observations of Mallory and others who have found large num- 

 bers of small microorganisms corresponding morphologically with 

 Bact. pertussis occurring between the cilia on tlie epithelial cells lining 

 the respiratory tract in fatal cases of the disease. 



HjEMORRHAGIC SEPTIC^MtAj 



Bacterium bomsepticum 



Haemorrhagic septicaemia belongs to a class of similar diseases 

 grouped under the general head of Pasteurelloses. 



This disease has been reported from many portioris of North 

 America, from some sections of South America and many European 

 countries. It is known under a variety of names, as cornstalk disease; 

 buffalo disease, pneumo-enteritis, etc. 



Bact. bomsepticttm produces a serious disease and affects a wide 

 variety of domestic and wild animals. The domestic animals most 

 commonly affected are cattle, sheep, and goats; the disease being much 

 more common among cattle than among other classes of stock. - 



The period of incubation in the artificial disease appears to be short, 

 six to forty-eight hours. The onset of disease is usually sudden, and 

 the case acutp. Haemorrhagic septicaemia does not spread from herd 

 to herd but appears in isolated outbreaks usually at wide distances 

 apart. It is a common experience to find a serious outbreak in one 

 herd without any appearance of the disease in another herd in an 

 adjoining pasture, with only a barbed wire fence between. Appar- 

 ently the virus exists locally and, under as yet unknown conditions 

 of increased virulence or lowered resistance, is able to start a local 

 outbreak. 



Haemorrhages found at autopsy constitute the most specific and char- 

 acteristic clinical evidence of this disease. Its mortality is very high, 

 running from 50 to 90 per cent. 



X Prepared by M. H. Reynolds. 



