236 BIOLOGY OF PNEUMOCOCCUS 



would define more accurately the condition and the possible menace 

 of the chronic class. 



Summary 



A summary of the main facts brought out in the foregoing dis- 

 cussion may be presented thus : 



1. The great majority of cases of lobar pneumonia (circa 96 

 per cent) are caused by Pneumococcus. 



2. Pneumococci of Types I and II are accountable for approxi- 

 mately one-half of the cases of lobar pneumonia in all countries 

 from which records are available, except Africa. 



3. The various serological types found in lobar pneumonia, as 

 far as at present known, are, in order of frequency, I, III, II, VIII, 

 VII, V, IV, XIV, XVIII. In children, pneumococci of the first 

 three types are responsible for the disease in only 36 per cent of 

 the cases, with Types XIV, I, VI, V, VII, IV, IX, XV, and XIX 

 occurring most frequently in the order given. 



4. The fatality-rates of pneumococcal lobar pneumonia have 

 been reported as 40 to 60 per cent for Type III cases, 41 for 

 Type II, 25 for Type I, with Types XVIII, VII, and VIII next 

 in order of lethal power. 



5. In bronchopneumonia, the types responsible for infection in 

 order of incidence are III, VIII, XVIII, X, V, VII, XX, II, XI, 

 and XIV. The data are tentative pending further information. 



6. Lobar pneumonia, although usually endemic, may, as is the 

 case of other bacterial infections of the respiratory tract, appear 

 in localized outbreaks, which are not the peculiar manifestation of 

 any particular type of Pneumococcus. 



7. As accompaniments or sequels of lobar pneumonia, infections 

 by the pneumococcus causing the primary lesion may arise in vari- 

 ous locations in the body, or 



8. Primary lesions incited by Pneumococcus may develop in the 

 eye, nasal, buccal, and aural cavities and adnexa, the meninges, 

 and other tissues. 



