358 DIPHTHERIA. 



the rest; often, however, they are rather tapered off (Fig. 

 119). In some cases the terminal swelling is very marked, so 

 as to amount to clubbing, and with some specimens of methy- 



lene-blue these 

 • swellings and 



granules stain 

 of a violet tint. 

 Distinct club- 

 bing, however, 

 is less frequent 

 than in cult- 

 ures. There is 

 a want of uni- 

 formity in the 

 appearance of 

 the baciUi if 

 compared side 

 by side. They 

 usually lie ir- 

 regularly scat- 

 tered or in 



Fig. 119. — Film preparation from diphtheria membrane; show- Clusters, ttiem- 



ing numerous diphtheria bacilli. One or two degenerated forms dividual bacilli 



are seen near the centre of the field. (Cultures made from the same , . , . , 



piece of membrane showed the organism to be present in practically oeing GlspOSeo 



pure condition.) in all direc- 



Stained with methylene-blue. X 1000. . „ 



tions. bome 

 may be contained within leucocytes. They do not form 

 chains, but occasionally forms longer than those mentioned may 

 be found, and these specially occur in the spaces between the 

 fibrin as seen in sections. 



Distribution of the Bacillus. — The diphtheria bacillus may 

 be found in the membrane wherever it is formed, and may also 

 occur in the secretions of the pharynx and larynx in the disease. 

 It may be mentioned that distinctions formerly drawn between 

 true diphtheria and non-diphtheritic conditions from the appear- 

 ance and site of the membrane, have no scientific value, the only 

 true criterion being the presence of the diphtheria bacillus. 

 The occurrence of a membranous formation produced by 

 streptococci has already been mentioned (p. 193). 



In diphtheria the membrane has a somewhat different struc- 



