SYMPTOMS 445 



preparation, the cocci were surrounded by a distinct envelope 

 which could be stained only with great difficulty and which 

 was absent from cultivated micrococci. 



Arloing believed that he had found the existing cause of 

 the disease in various bacilli, especially in one which he calls 

 Pyieumo-bacillus liquefaciens bovis, which forms short nonmotile 

 rods. Arloing believes that his experiments prove that the 

 pneumo-bacillus is the cause of pleuro-pneumonia. 



In 1898, Nocard and Roux succeeded in obtaining a very 

 feeble growth of an exceedingly minute organism in bouillon 

 containing cow or rabbit serum in proportion of one part 

 serum to 25 parts bouillon, when cultivated in collodion sacs 

 within the abdominal cavity of rabbits. The rabbits which 

 received the inoculated capsules become emaciated, and some 

 of them died. Those inoculated with uninoculated capsules 

 remained well. Rabbits inoculated with the pleuro-pneumonic 

 lungs were not affected. With the cultures obtained in the 

 collodian sacs the disease was produced in cattle. The virus 

 passed through a Berkefeld filter and Chamberland F cylinder 

 but it was held back by a Chamberland filter B. 



§ 354- Symptoms. The symptoms are such as would 

 be expected with inflammation of the lungs and pleurae, but 

 they vary considerably according to the course which the 

 disease runs. If the attack is an acute one, as is frequently 

 seen in hot weather, the symptoms appear suddenly. The 

 breathing becomes rapid and difficult, the animal grunts or 

 moans with each expiration, the shoulders stand out from the 

 chest, the head is extended on the neck, the back is arched, 

 the temperature ranges from 104 to 107" F., the milk secretion 

 is suspended, there is loss of appetite, rumination is stopped, 

 the animal may bloat and later be affected with a severe 

 diarrhea. Such cases are generally fatal in from seven to 

 twenty daj'S. 



Very often the attack comes on slowly and the symptoms 

 are more obscure. In the mildest cases there is a cough for a 

 week or two but no appreciable loss of appetite or elevation of 

 temperature. The lungs are but slightly affected and recovery 



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