8o THE GROUSE DISEASE chap. 



pletely by the researches of Perroncito, Toussaint, 

 Pasteur, Kitt, and others. 



The disease fowl cholera or chicken cholera, rife 

 in France and Germany, is an acute infectious dis- 

 ease, rapidly fatal, and producing great devastations 

 amongst fowls. After an incubation of from i6 or 

 1 8 hours to a day or a day and a half, the fowls 

 show the first symptoms of the disease — diarrhoea of 

 thin, greenish, mucoid evacuations, unwillingness to 

 move, and quietness ; they refuse food ; they soon 

 become drowsy and somnolent, and this rapidly in- 

 creasing, leads to death in from 24 to 36 or 48 

 hours. On post-mortem examination the heart is 

 distended and filled with blood that rapidly clots, 

 the lungs, liver, spleen, intestines, and peritoneum 

 are found much congested ; in the lungs, liver, and 

 intestine, particularly the duodenum and in the peri- 

 toneum, haemorrhages occur in the form of petechias 

 and patch-like blood effusions. The blood of the 

 heart and the general circulation is crowded with 

 minute oval or short rod-like bacteria, known as the 

 bacilli of fowl cholera ; their number is generally as 

 great, often greater, than that of the blood-corpuscles 

 (Figs. 32, 33, and 34). In stained preparations the 

 rods show a characteristic deeply stained granule at 

 each end, the middle part of the rod being clear; 

 hence at first sight it appears like a dumb-bell. Some 



