514 INFECTION AND IMMUNITY. 



organisms. It is undoubtedly in the last named 

 manner that meningitis, endocarditis., arthritis, 

 and muscular and subcutaneous abscesses arise. 



Rosenow has isolated from endocarditis cases 

 pneumococci differing from the usual type in that 

 they grow in clumps and adhere more or less 

 closely to the surface of blood-agar slants. They 

 grow in chains and produce less green on blood- 

 agar plates than do pneumococci of the usual type. 

 In animal inoculation a tendency to localize on 

 endothelial surfaces is shown. 



of Other infections by the pneumococcus occur in- 

 dependent of the existence of pneumonia. Such 

 conditions are alveolar abscesses, conjunctivitis, 

 dacryocystitis, serpent ulcer of the cornea, in- 

 flammation of the middle ear, meningitis, enteri- 

 tis, rarely peritonitis, and pneumococcus septice- 

 mia which may be complicated by infection in vari- 

 ous organs. The eye is exposed to infection from 

 without and the ear from the pharynx. Primary 

 pneumococcus meningitis occurs both sporadically 

 and epidemically, although the meningococcus is 

 a much more frequent cause. The organisms may 

 gain entrance through the middle ear or nose, or 

 through the circulation from a primary focus in 

 another organ, perhaps an undiscovered focus. Pre- 

 ceding and during meningitis the nose is not in- 

 frequently the seat of pneumococcus rhinitis, and 

 the organisms may be carried from the nose to the 

 meninges by way of the lymph channels. The 

 blood may be infected secondarily. Pneumococcus 

 meningitis is almost invariably fatal. The organ- 

 ism causes chronic meningitis less frequently than 

 the meningococcus. Infection of the peritoneum 



