I«5 CLINICAL VKTERINARY MEDICINK AND SURCERY. 



a few hours, developing in the usual way and producing necrotic 

 lesions in the lung and degenerative changes in the viscera. In con- 

 tradistinction to the pneumococcus of man, which is delicate and 

 ephemeral, and sometimes disappears from the lesions after a very few 

 days, the bacteria in question show considerable resistance to destruc- 

 tive influences. In patients which survive they may long preserve their 

 vitality, multiplying in the necrotic centres surrounded by a zone of 

 fibrous tissue, and when these centres are in communication with the 

 bronchi being continually discharged, and rendering the nasal dis- 

 charge virulent for months. Convalescent or apparently cured cases 

 in which the lung contains such centres long remain dangerous. They 

 perpetuate the disease in certain stables, or introduce it into other 

 previously healthy quarters, where the first cases are naturally referred 

 to the action of atmospheric changes. 



Though admitted by some authors, the specific character of this 

 microbe and the powers attributed to it by Schiitz have been contested 

 by others, especially by Hell and Baumgarten. In i8go Hell under- 

 took certain researches consisting in cultivating, staining, and inocu- 

 lating with the organism, in order to determine the analogies and 

 differences which existed between it and the several streptococci. From 

 them he concluded that by the bacteriological methods then in use no 

 clearly marked difference could be established between the microbe in 

 question on the one hand, and the Streptococcus pyogenes of the horse 

 and the streptococcus of erysipelas in man on the other ; and further- 

 more, that these species are similar from the morphological and 

 biological points of view, and from the manner in which they behave 

 when inoculated.* 



'■' Recent researches by W. Lignieres seem to show that the microbe described by 

 Schiitz is the streptococcus of strangles, and that it only plays a secondary part in the 

 aetiology of pneumonia in the horse. It is generally, but not always, found in the lungs of 

 horses dead of pneumonia. The true microbe of pneumonia is said to be the " cocco-bacille 

 typhiqiie^' of the order Pasteiirella.' This micro-organism, which >grows as a saprophyte in 

 forage, manure, water, and soil, and becomes pathogenic under the influence of causes at 

 present unknown, appears as a monococcus, diplococcus, or as a little bacillus with rounded 

 extremities. The last is the "true" form of the microbe ; at the moment when it divides it 

 appears as a diplococcus. The monococci result from complete and recent separation of 

 the diplococci. Finally, under certain conditions these microbes take the form of " strepto- 

 cocco-bacilUy The organism is aerobic, produces no spores, and is killed in less than a 

 quarter of an hour by a temperature of 65"^ C, but grows freely in peptonised bouillon and 

 on gelatine at 20° C. It is pathogenic for the guinea-pig, rabbit, and horse, and rapidly kills 

 these animals on subcutineous inoculation. M. Lignieres has found it in cases of pleurisy, 

 infectious pleuro-pneumonia, in broncho-pneumonia, and in infectious sore throat, in 

 pneumonia a frigore, in the abdominal form of influenza, in the pneumonia of strangles, and in 

 " stable pneumonia." All these affections are said to be but varieties of " Pasteurellosis." 



Infectious pneumonia is due to the " hacillc typhiqur" which is able to multiply in 



