200 



THE ACUTE PNEUMONIAS 



rod forms may occur (Fig. 65). 





The capsule has the same 

 general characters as 

 that of FraenkePs organ- 

 ism. JFriedlanderV 

 pneumobacillus stains 

 readily with the basic 

 aniline stains, but loses 

 the stain in Gram's 



method, and is accord- 

 ingly coloured with the 

 contrast stain, fuchsin 

 or Bismarck -brown, as 

 above recommended. A 

 valuable means is thus 

 afforded of distinguish- 

 ing it from Fraenkel's 

 pneumococcus in inicro- 



Fio. 65. Friedlander's pneumobacillus, showing scopic preparations, 

 the variations in length, also capsules. Film 

 preparation from exudate in a case of pneu- 

 monia, x 1000. 



sometimes it 



Friedlander's organ- 

 ism is much less fre- 

 quently present in pneu- 

 is associated with the 



inonia than Fraenkel's; 

 latter; very rarely it 

 occurs alone. 



In sputum prepara- 

 tions the capsule of both 

 pneumococci may not be 

 recognisable, and the 

 same is sometimes true 

 of lung preparations. 

 This is probably due to 

 changes which occur in 

 the capsule as the result 

 of changes in the vitality 

 of the organisms. Some- 

 times in preparations 

 stained by ordinary 

 methods the difficulty of 

 recognising the capsule 

 when it is present, is 

 due to the refractive 

 index of the fluid in 

 which the specimen is 

 mounted being almost identical with that of the capsule. 



FIG. 66. Fraenkel's pneumococcus in serous 

 exudation at site of inoculation in a rabbit, 

 showing capsules stained. 

 Stained by Rd. Muir's method. x 1000. 



This 



