228 



THE ACUTE PNEUMONIAS 



may occur 



(Fig- 



FIG. 63. Friedlander's pneumobacillus, show- 

 ing the variations in length, also capsules. 

 Film preparation from exudate in a case of 



pneumona, 



1000. 



pneumonia than Fraenkel's 

 latter; very rarely it 

 occurs alone. 



In sputum prepara- 

 tions the capsule of 

 both pneurnobacteria 

 may not be recognis- 

 able, and the same is 

 sometimes true of lung 

 preparations. This is 

 probably due to changes 

 which occur in the cap- 

 sule as the result of 

 changes in the vitality 

 of the- organisms. Some- 

 times in preparations 

 stained by ordinary 

 methods the difficulty 

 of recognising the cap- 

 sule when it is present, 

 is due to the refractive 

 index of the fluid in 

 which the specimen is 



capsule has the same general 

 characters as that of 

 Fraenkel's organism. 

 Friedlander's pneumo- 

 bacillus stains readily 

 with the basic aniline 

 stains, but loses the 

 stain in Gram's method, 

 and is accordingly col- 

 oured with the contrast 

 stain, fuchsin or Bis- 

 marck-brown, as above 

 recommended. A valu- 

 able means is thus 

 afforded of distinguish- 

 ing it from Fraenkel's 

 pneumococcus in micro- 

 scopic preparations. 



Friedlander's organ- 

 ism is much less fre- 

 quently present in 

 sometimes it is associated with the 



FIG. 64. Fraenkel's pneumococcus in serous 

 exudation at site of inoculation in a rabbit, 

 showing capsules stained. 

 Stained bv Rd. Muir's method, x 1000. 



mounted being almost identical with 



