316 Manual of Veterinary Microhiology . 



spleen is much enlarged. The diplococcus pneumo- 

 enteritis equi has a less pronounced dissolving action 

 on the blood corpuscles. Inoculation to the horse 

 causes pneumonia; this disease develops as a conse- 

 quence of injection into the lungs, trachea, or circu- 

 lation, but only rarely as a result of ingestion. 



According to Galtier and Violet, the disease origi- 

 nates when horses are fed on forage of bad quality, 

 such as soiled, moldy, or rusty hay, and imperfectly 

 harvested and damaged grain. These damaged foods 

 are the bearers of the germs of the disease and it is 

 by their intermediation that these germs obtain entry 

 to the system. The dust rising from the fodder en- 

 ters the respiratory passages, where the microbes 

 which it carries along act directly upon the lung. 

 The disease has, in fact, been produced in the horse 

 by inoculation of the products obtained by macera- 

 tion of suspected foods. 



The disease can then be transmitted from one ani- 

 mal to another by the excrements and nasal dis- 

 charge; contagion, according to Galtier, plays an ac- 

 cessory part; the diffusion of the cause suffices to 

 explain the enzootic and even epizootic character of 

 the aifection. Its transmission, however, can not be 

 doubted. 



Contagious pleuro-pneumonia of cattle. 



Microbe. — M. Arloing found that the serosity 

 which flows from the surface of a section through a 

 diseased lung is very poor in microbes and that the 

 majority of the culture bulbs inoculated with a small 

 quantity of this serosity remain sterile. To obtain 

 fertile cultures a large quantity of this serosity must 



