178 3Ianual of Veterinary Microbiology. 



petence, diarrhoea, chilliness, ruffling of the plumage, 

 etc. The temperature, at first high, afterward de- 

 scends one to two degrees below the normal figure ; 

 the aniaial dies on the ninth to the thirteenth day after 

 the beginning of the disease, occasionally much later. 



The bacteria, which are present in most of the 

 lesions and especially in the intestine, show them- 

 selves in the form of short bacilli 1-2/i to 1*8// in 

 length, occasionally isolated, more frequently united 

 in pairs, motile, at once aerobic and anaerobic, rap- 

 idly becoming attenuated in cultures. 



The disease is communicated, by ingestion of viru- 

 lent products, from chicken to duck, and inversely. 

 Inoculation of cultures also causes it in the same fowls; 

 but ingestion of cultures only produces the disease 

 when the diet is changed at the same time. The 

 pigeon and the guinea pig are refractory ; the rabbit 

 takes the disease only by intravenous inoculation; 

 subcutaneous injection remains without effect. 



Duck cholera. 



Ducks are liable to contract chicken cholera ; in ad- 

 dition, they may be attacked by another contagious 

 disease which is also characterized by diarrhoea, 

 emaciation of the affected subjects, and by its usually 

 fatal termination; it has been described under the 

 name of duck cholera. 



This disease is caused by the multiplication in the 

 blood of a bacterium presenting the greatest mor- 

 phological analogies with that of chicken cholera; it 

 is oblong, short, and appears bi-lobed in stained 

 preparations on account of the greater affinity of its 

 extremities for the coloring matters. The microbes 



