Microbie Diseases Individually Considered. 178 



quickly becomes clouded and at the end of several 

 days clears again by tlie deposition of tlie micro- 

 organisms. 



Gelatin inoculated in lines becomes covered along 

 the latter by a raised transparent pellicle; inoculated 

 by puncture it shows small gray colonies all along 

 the needle track; it is not fluidified. 



The culture succeeds very indifferently on potato. 



Research and coloration. — The microbes of chicken 

 cholera are easily distinguished, under strong mag- 

 nification, in uneolored preparations of fresh blood; 

 they appear as very refringent, mobile diplo-cocci. 

 They must be stained with the hydro-alcoholic solu- 

 tions as they are decolorized by the Gram method; 

 Lofiler's method is most suitable, especially when it 

 is desired to study the microbes in sections. 



Exjperimental inoculations. — The disease prevails 

 spontaneously in and is successfully inoculated to all 

 species of poultry: chickens, ducks, geese, pigeons, 

 and turkeys; the pheasant and sparrow are also sus- 

 ceptible. Subcutaneous inoculation and ingestion 

 give results almost equally certain. The introduc- 

 tion of the virulent matter into the pectoral muscle, 

 by means of the Pravaz syringe, causes the formation 

 of a sequestrum which is the more pronounced as 

 the experimental disease is of longer duration. This 

 sequestrum, however, is not characteristic of the dis- 

 ease ; it may be seen after the injection of other germs 

 (those of pneumo-enteritis of the pig, the spontane- 

 ous rabbit septicsemia of Thoinot and Masseliu, and 

 a number of septic bacteria). 



The rabbit is extremely sensitive to chicken chol- 

 era. The subcutaneous injection of a drop of blood 



