326 BACTERIOLOGY. 



duodenum for as long a time as possible, the animal was 

 to receive, immediately following the injection of the 

 culture, an intra-peritoneal injection, by means of a 

 hypodermatic syringe, of 1 c.c. of tincture of opium 

 for each 200 grammes of its body weight. Shortly 

 after this last injection a deep narcosis sets in and lasts 

 from a half to one hour, after which the animal is 

 again as lively as ever. Of 35 guinea-pigs inoculated 

 in this way by Koch, 30 died of a condition that was, 

 in general, very similar to that seen in Asiatic cholera. 



The condition of these animals before death is de- 

 scribed as follows : Twenty-four hours after the opera- 

 tion the animal appears sick ; there is a loss of appetite, 

 and the animal remains quiet in its cage. On the 

 following day a paralytic condition of the bind extre- 

 mities appears, which, as the day goes on, becomes more 

 pronounced ; the animal lies quite flat upon its ab- 

 domen or on its side, with its legs extended ; respiration 

 is weak and prolonged, and the pulsations of the heart 

 are hardly perceptible ; the head and extremities are 

 cold, and the body temperature is frequently subnormal. 



The animal usually dies after remaining in this 

 condition for a few hours. 



At autopsy the small intestine is found to be deeply 

 injected and filled with a flocculent, colorless fluid. 

 The stomach and intestines do not contain solid masses, 

 but fluid ; when diarrhoea does not occur, iirm scybala 

 may be expected in the rectum. Both by microscopic 

 examination and by culture methods, comma bacilli are 

 found to be present in the small intestine in practically 

 pure culture. 



More recently Pfeiifer' has determined that essentially 



1 Zeitsohrift filr Hygiene, Bd., xi. and xiv. 



