606 BACTERIA IN INFECTIOUS DISEASES. 



Bacillus hyacinth! septicus (Heinz) of an infectious disease of hyacinths ; Ba- 

 cillus amylobacter of potato rot (Nassfaule) ; Bacillus tracheiphilus (E. F. 

 Smith) of blight in melons and other cucurbitacese. 



PLEURITIS, 



The usual infectious agent in acute fibrinous pleurisy accompany- 

 ing pneumonia is Micrococcus pneumonia? crouposa? (No. 8). Net- 

 ter (1892) reports that in 66 cases of genuine fibrinous pleurisy in 

 which he has made bacteriological researches since 1886, he has 

 always found this micrococcus. In cases in which culture experi- 

 ments give a negative result, this is, according to Netter, due to the 

 fact that the micrococci are apt to perish at the crisis of the disease. 

 These cases do not usually result in empyema and run a more favor- 

 able course than those in which the pus cocci are present. Prudden 

 (1893) in 21 cases of sero-fibrinous pleurisy failed to find any bac- 

 teria in the exudate in 1*2, and found the micrococcus of pneumonia 

 in 2 only. Lemoine (1895) also reports that in 28 cases, out of 32 

 examined by him, the exudate was entirely sterile; in 4 cases he 

 found Staphylococcus pyogenes albus. The remaining cases were of 

 tubercular origin. 



Levy (1895), in reviewing the literature of the subject, arrives at 

 the conclusion that the micrococcus of pneumonia is the usual cause 

 of pleurisy in children and of metapneumonic pleurisy, but that in 

 metastatic, pysemic, pleuritic inflammation streptococci or staphylo- 

 cocci are the usual infectious agents. Pleurisy due to streptococcus 

 or staphlyococcus infection is not in all cases attended with pus for- 

 mation ; the exudate, in a certain proportion of the cases, may remain 

 serous (Levy, Ludwig, Goldschneider) . 



The micrococcus of pneumonia was found by Jakowski (1892) in 

 21 out of 34 cases in which pure cultures were obtained ; of the re- 

 maining cases streptococci were found in 10, Staphylococcus pyogenes 

 aureus in 1, and the tubercle bacillus in 2. In 14 cases of mixed 

 infection Staphylococcus pyogenes aureus and albus were found in 

 6, Friedlander's bacillus and streptococci in 1; the micrococcus of 

 pneumonia with streptococci in 1, with Staphylococcus pyogenes 

 albus in 2, and with Staphylococcus pyogenes aureus in 1. In 7 

 cases no bacteria were found. According to Jakowski those cases 

 in which no bacteria are obtained in cultures are usually due to 

 tubercular infection. Goldschneider (1892) reports 4 cases of serous 

 pleurisy, in 3 of which he found Streptococcus pyogenes and in 1 

 Staphylococcus pyogenes aureus. Bordoni-Uffreduzzi (1895) has re- 

 ported a case of double pleurisy in a girl, aged twelve, who was 

 assaulted by an individual with gonorrhoea, in which the gonococ- 

 cus was the only microorganism present in the pleural exudate. 



