PNEUMONIA 



245 



1892), who worked on pneumonic material from various 

 sources ; they found these organisms, which were remark- 

 able for their virulence, to be chiefly diplococci. The Pseudo- 

 diplococcvs 'pnewnonim, described by Sternberg as discovered 

 by Bonome in 1889, is probably a member of this group, 

 J. Washbourn (in a paper read before the Pathological 

 Society of London, and printed in the Journal of Pathology 

 and Bacteriology) does not appear to have met with 

 organisms of varying virulence, but in other respects his 

 experiences confirm those of other observers, particularly 

 as regards growing the organism (Sternberg's micrococcus) 

 for any length of time on artificial media. 



Both organisms may be found in the blood, and are 

 surrounded by a capsule, the substance of which is soluble 

 in water. When found in the blood or cultivated in broth,, 

 both organisms are apt to be lanceolate in form, instead of 

 spherical, while on solid media they are generally round. 

 They sometimes occur three or four together, and on agar 

 may grow out into long chains. 



Method of Staining. — The micrococcus of pneumonia stains 

 with Gram's method of staining, the diplo-bacillus of Fried- 

 lander is decolourised, while they both stain with all the 

 ordinary basic aniline dyes. The two organisms are very 

 similar in microscopic appearance, but are readily distin- 

 guished by their cultural differences. 



Growth on Media. — The following table shows the chief 

 points of difference : 



