40 EQUINE PLEURO-PNEUMONIA 



cultures, however, they appeared in long chains, leaving the 

 liquid clear, as described bj' Schiitz. 



This streptococcus did not grow in gelatin, or on serum, or 

 on potato. It would not develop in acid media. On agar, the 

 colonies were small and characteristic of streptococci, i. e., 

 with a thickened, convex, grayish center surrounded by a 

 thin, spreading bluish border, nearly equal in width to the 

 diameter of the central portion. It fermented dextrose, lac- 

 tose and saccharose, with the formation of acids but no gas. 

 Milk remained unchanged in appearance. 



In mice and rabbits, it produced a rapidly fatal septicaemia, 

 but guinea-pigs were unaffected. A horse inoculated in the 

 pleural cavity with a small quantity of the culture was killed 

 ID da>'s later. At the point of inoculation and extending 

 over an area equal to one-half of the lung, there were strong 

 adhesions between the lung and parietes. The subjacent lung 

 tissue was hepatized. Pure cultures of the streptococcus were 

 obtained from the exudate and from the hepatized lung. 



Although a few discrepancies exist between the descrip- 

 tion of Schiitz's organism and this streptococcus, in the more 

 essential features they seem to be identical. The cases were 

 examined before the publication of I^ignieres' results, and the 

 methods employed did not meet the requirements of those 

 used in isolating his cocco-bacillus. Although a very careful 

 histological study of the pneumonic tissue was made, Lig- 

 niere's organism was not detected. 



§ 32. Symptoms. The period of incubation is given 

 as varying from one to fourteen days, but usually from four 

 to ten daj's elapse from the time of exposure to the de- 

 velopment of the first .symptoms. The symptoms vary to a 

 marked degree. When pneumonia develops early in its 

 course, the disease may appear suddenly ; and, in addition to 

 the elevation of temperature, there is cough and difficult 

 breathing. Often the symptoms differ from those of fibrinous 

 pneumonia by the absence of distinct evidences of local lesions 

 which are found in that disease. The first regular symptom 

 is a rapidh- increasing temperature frequently accompanied 

 by a chill. The pulse rate is increased. There is general 



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