368 PATHOGENIC MICROORGANISMS 



on agar are moister and flatter, and the freshly isolated pneumococcus 

 is usually unable to develop readily or at all on gelatin at below 22 C. 

 The distinctness of the capsule of the pneumococcus in the body 

 fluids of man and animals and on blood serum, milk, or serum agar, 

 has been depended upon as the chief distinguishing and diagnostic 

 character. Nevertheless, instances have been reported of distinct cap- 

 sule formation by organisms which had either been previously iden- 

 tified as Streptococcus pyogenes, or at the time of their isolatoin could 

 not be definitely identified as belonging to this group or to the pneu- 

 mococci, but were considered intermediate in character, 1 



1 Brief Description of Organisms Reported as Capsulated Streptococci. Bordet 

 (Bordet, Ann. de 1'inst. Pasteur, 1897, xi, p. 177), working with an organism previously 

 identified as Streptococcus pyogenes, described such capsule formation occurring in 

 the peritoneal exudate of infected rabbits. 



Schuetz' (Schuetz, Cent. f. Bakt., Ref. 1, 1887, p. 393) Biplokokkus der Brust- 

 seuche der Pferde, Poels and Nolen's (Poels und Nolen, Fort. d. Med., iv, 1886, p. 217) 

 streptococcus of contagious pneumonia of cattle, and especially the organism de- 

 scribed by Bonome (Bonome, Ziegler's Beit., viii, 1890, p. 377) as Streptococcus 

 der meningitis cerebrospinalis epidemica, may all be looked upon as organisms 

 differentiated on insecure grounds from either pneumococcus or streptococcus. The 

 first two of these organisms, however, are said to be decolorized by Gram's method, 

 and as suggested by Frosch and Kolle (Frosch und Kolle, Fliigge's " Mikro-organis.," 

 ii, 1896, p. 161), in the case of Schuetz' organism may belong to a group inter- 

 mediate between Fraenkel's diplococcus and the chicken-cholera group. 



Tavel and Krumbein (Tavel und Krumbein, Cent. f. Bakt., xviii, 1895, p. 547) 

 describe a streptococcus with a capsule, which was isolated from a small abscess on 

 the finger of a child. Capsules were also present in the artificial cultures, and al- 

 though ordinarily remaining uncolored, could be stained by Loeffler's flagella stain. 

 This organism was said to be differentiated from Fraenkel's diplococcus and also in 

 general from streptococcus (pyogenes) by a rapid and rich growth on gelatin, agar, 

 and potato. A pellicle was formed on broth. The organisms forming this pellicle 

 had capsules, but those in the deeper portions of the broth generally lacked it. 



In 1897, Binaghi (Binaghi, Cent. f. Bakt., xxii, 1897, p. 273) described a cap- 

 sulated streptococcus isolated from a guinea-pig dead of a spontaneous peribron- 

 chitis and multiple pulmonary abscesses. In the pus were found some diplococci and 

 short chains (four to six) surrounded by a capsule, shown by staining with carbol 

 fuchsin. This organism he proposes to call Streptococcus capsulatus. 



Le Roy des Barres and Weinberg in 1899 (Le Roy des Barres et Weinberg, Arch, 

 d. me*d. exper., xi, 1899, p. 399) published an account of a streptococcus with a 

 capsule. This was isolated from a man who had apparently been infected from a 

 horse which had died of an acute intestinal disorder. The patient neglected the 

 infection and died. Diplococci and short chains furnished with a capsule were 

 found in the subcutaneous tissue at the area of infection. The blood, liver, and 

 spleen also contained these organisms. The capsule in all the preparations remained 

 uncolored, but the authors say that its existence was not to be doubted. Ascitic 



