BACTERIA IN PNEUMONIA 227 



the lungs immediately after death (as may be quite well done 

 by means of a hypodermic syringe), putrefactive and other 

 bacteria may be present, but those to be looked for are capsulated 

 organisms, which may be of either or both of the varieties 

 mentioned. 



(1) FraenkeVs Pneumococcus. This organism occurs in the 

 form of a small oval coccus, about 1 p. in longest diameter, 

 arranged generally in pairs (diplococci), but also in chains of 

 four to ten (Fig. 62). The free ends are often pointed like a 

 lancet, hence the term 



diplococcus lanceolatus .% ... 



has also been applied to .X ' , '/; * 



it. These cocci, in their .>" 



typical form, have round /^ * * ''* '. 



them a capsule, which, in /j* f t . - 



films stained by ordinary ^ f 



methods, usually appears I , . , tf 



as an unstained halo, but 1 ; >/ 



is sometimes stained more \ ji v , t " s, s ' 



deeply than the ground V?; ,* * 



of the preparation. This 



difference in staining de- >/ 



pends, in part at least, on 



the amount of decolorisa- 



tiou to which the prepara- m ^ _ p . lm prepftrations of pneumonic 



tlOll lias been subjected. sputum, showing numerous pneumococci 



The capsule is rather (Fraenkel's) with unstained capsules ; 



Kr^urlor tkan tlia KrtrJv sonie are arranged in short chains. See 

 broader tnan tne boay algo plate j ^ F ? g 2 



of the coccus, and has a Stained with carbol fuchsin. x 1000. 



sharply defined external 



margin. Often in sputum and even in the lung no capsule can 

 be demonstrated. The organism takes up the basic aniline 

 stains with great readiness, and also retains the stain in Gram's 

 method. It is the organism of by far the most frequent occur- 

 rence in true croupous pneumonia, and in fact may be said to 

 be rarely absent. 



(2) Friedldnder's Pneumobacillus. As seen in the sputum 

 and tissues, this organism, both in its appearance and arrange- 

 ment, as also in the presence of a capsule, somewhat resembles 

 Fraenkel's pneumococcus, and it was at first described as the 

 " pneumococcus." The form, however, is more of a short rod- 

 shape, and it has blunt rounded ends ; it is also rather broader 

 than Fraenkel's pneumococcus. It is now classed amongst the 



illi, especially in view of the fact that elongated rod forms 



