406 APPLICATION OF METHODS OF BACTERIOLOGY 



It must be remembered, however, that this organism when 

 cultivated for a time on artificial media may lose rapidly 

 its pathogenic properties. If, therefore, failure to reproduce 

 the disease after inoculation with old cultures should occur, 

 it is in all probability due to such loss of virulence. 



This organism was discovered by Sternberg in 1880. It 

 was subsequently described by A. Frankel as the etiological 

 factor in the production of actue fibrinous pneumonia. 



It is not uncommonly present in the saliva of healthy 

 individuals, having been found by Sternberg in the oral 

 cavities of about 20 per cent, of healthy persons examined 

 by him, and certain Authors are of the opinion that it occurs 

 in the oral or nasal cavities of all individuals at one time 

 or another during life. It is constantly to be detected in 

 the rusty sputum of patients suffering from acute fibrinous 

 pneumonia. Its presence has been noted in the middle ear, 

 in the pericardial sac, in the pleura, and in the serous cavities 

 of the brain; and indeed it may penetrate from its usual 

 site of development in the mouth to any of the more distant 

 organs. 



The organism is commonly found as a diplococcus, though 

 here and there short chains of four to six individuals may 

 be seen. (Fig. 75.) The individual cells are more or less 

 oval, or, more strictly speaking, lancet-shaped, for at one 

 end they are commonly pointed. When joined in pairs the 

 junction is always at the broad ends of the ovals. When 

 in chains only the terminal cells are pointed, and then at 

 their distal extremities. 



As already stated, in preparations directly from the sputum 

 or from the blood of animals a delicate capsule may fre- 

 quently be seen surrounding them. Though fairly constant 

 in preparations directly from the blood of animals and from 



