520 EXPERIMENTAL RESEARCHES WITH CHICKEN-CHOLERA MICROBES, 



to be blamed for the negative issue, because other rabbits treated 

 under exactly the same conditions promptly perished. Be that 

 as it may. That such rabbits as resisted in the first instance, were 

 not, or had not become protected against the disease — except the 

 tame rabbit mentioned, the history of which is given on pp. 522- 

 525 — was proved by their succumbing to it when they were in a 

 satisfactory manner fed, in the second instance, on 2 ccra. of broth- 

 culture, some time afterwards (one rabbit, however, died more than 

 2J days after the first feeding, from some indifi'erent cause, and 

 another was lost sight of, before the ultimate proof of its sus- 

 ceptibility or otherwise could be given). 



It has already been pointed out that the disease set up by the 

 chicken-cholera microbes in rabbits, both by inoculation and 

 feeding, mostly takes a rapid course. Although the term ''chicken- 

 cholera" for the disease caused by the microbes in rabbits, is in- 

 appropriate, I have made use of it for the sake of brevity and a 

 better understanding. 



The incubation occupies most of the time, the symptoms, or the 

 actual disease being only of short duration. Death occurs under 

 clonic cramps, and dyspnoea. Observations about the body- 

 temperature during the disease, and some data regarding the 

 breathing at the end of it, will be found in connection with experi- 

 ments on the transmission of the disease from rabbit to rabbit 

 (see pp. 554, 555, Table III.). 



At the post-mortem examination one finds the following notice- 

 able features : — The heart is filled with blood. The lungs are dis- 

 coloured ; they are very voluminous owing to an emphysematic 

 oedema involving their entire substance (on cutting through with 

 a pair of forceps, or a scalpel, a crepitant sound is heard, and 

 froth left on the blades of the instruments). Their surface pre- 

 sented a shining, mottled or tesselated appearance, due to ecchy- 

 moses or haemorrhages in the lungs. 



Pleura and peritoneum were mostly inflamed. The pleural, 

 pericardial, and peritoneal cavities filled, as a rule, with serous 

 exudations. 



