SPECIAL FOEMS OF CONJUNCTIVAL INFECTION 163 



The individuals are, on an average, 2 to 3 /* long and 1 to T5 ^ broad. 

 The size varies, and much smaller ones are seen ; these are probably 

 younger. Larger forms also occur. 



The bacilli are rounded off at their ends, like a truncated oblong ; 

 they are generally of even thickness. Sometimes the ends appear 

 a little swollen, and then a slightly deeper staining occurs there; 

 but polar staining is not general. The whole organism takes on the 

 stain very intensely. The line of separation between the pairs is 

 quite clear. 



Decolorization by Gram is rapid and complete. Concerning the 

 presence of a capsule, opinions vary. Morax calls the organism 

 capsule-free ; Axenfeld said ^^^^ 



that the capsule was not 

 clearly seen. On the con- 

 trary, Birnbacher and Gifford 

 state that the capsule is quite 

 obvious ; Hoffmann and Zur 

 Nedden hold the same view. 



Capsule staining in my 

 laboratory by Bietti and 

 Agricola showed the presence 

 of a narrow ectoplasm. Such 

 methods show capsules on 

 very many bacilli e.g., even 

 on anthrax. In a secretion 

 preparation we can say that 

 the majority of the Diplo- 

 bacilli, without special stain- 

 ing and with a wide aperture, 

 show no definite capsule. This is especially the case with preparations 

 stained by Gram's method, and counter-stained with safranin, such as 

 are shown in Plate I., Fig. III., exactly drawn from Nature. In these 

 respects the Diplococci differ greatly from Friedlander's Pneumobacillus 

 and the ozaena bacillus, which might otherwise be confused ; and it is 

 therefore correct to consider the capsule in the Diplobacilli un- 

 important. For other points refer to the remarks in Chapter I. on 

 capsule staining. 



Cultures. 



The Diplobacilli of the Morax-Axenfeld type only grow at brood 

 temperature, and then with certainty only on blood-serum, agar con- 

 taining serum, or media which contain human body fluids. 



11 2 



FlG. 22. DlPLOBACILLARY CONJUNCTIVITIS 



SECRETION (KYMOWITSCH AND 



MATSCHINSKY). x 1,000. 



