Contagious Pneumonia in the Horse. 99 



rabbit, subcutem, it usually killed in 24 to 48 hours, but some 

 survived ; intravenously or intratracheal it killed more certainly 

 and speedily and in either case with pleural, pericardial and even 

 peritoneal lesions. In the Guineapig , subcutem, it caused ex- 

 tensive effusion, and death in two to six days with chest lesions. 

 In the dog it caused hyperthermia, but no marked lesion and no 

 mortality. In the horse there were no infectious resultant 

 lesions. A pure culture thrown into the lung tissue of an old 

 horse at the N. Y. S. V. College, determined an extended pleuritic 

 adhesion and lung hepatization. The age of this subject was op- 

 posed to any marked susceptibility. The apparent immunity of 

 the horse in Schutze's cases might depend on the insusceptibility 

 of the animals selected during or after an epizootic, or on the 

 absence of the predisposing causes so strongly insisted on by 

 Cadeac. 



Rats, chickens and pigs proved immune. 



On peptonized gelatin at 98° F., and less rapidly at ordinary 

 temperature, it grew as white, opaque, colonies which gradually 

 extended and united in many cases. The gelatin was not lique- 

 fied. In peptonized bouillon it produces turbidity for one or two 

 days, after which the microbe precipitates leaving the liquid clear. 

 The reaction is unchanged. 



It lost virulence rapidly when kept in artificial culture or at a 

 temperature of 122° F. , and was killed by a temperature of 

 150° F. Yet it survived drying at moderate temperatures. 

 Cadeac found that the dried expectoration or blood, diffused in 

 the inspired air produced pneumonia with certainty in solipeds. 

 Schiitz and Fiedaler injected pure cultures into the lung, and in 

 other cases into the trachea, thereby inducing pneumonia. 

 Twenty grammes of the culture injected into the trachea raised 

 the temperature 2" or 3°, but this lessened on repetition and 

 after four or five treatments the subject proved immune. 



Ligni^res (1897) discovered his cocco-bacillus in the exudation 

 in the tissues in the early .stages of contagious pneumonia, from 

 which it disappears, giving place to other bacteria, and usually 

 streptococcus, as the disease reaches its maximum. (See Equine 

 Influenza for description). His theory is that the cocco-bacillus, 

 which is slightly smaller than the bacillus of chicken cholera, 

 and appears like a diplococcus when stained, and which may not 

 be found after the finst eight days of infectious pneumonia, is the 



