234 



THE ACUTE PNEUMONIAS 



on the surface of the pleura, and a similar condition in the 

 peritoneum, may occur. It may also be said that if a rabbit be 

 immunised with dead or attenuated cultures and then injected 

 with a virulent culture, similar local reactions may occur at the 

 inoculation site. In sheep greater immunity is marked by the 

 occurrence, after subcutaneous inoculation, of an enormous local 

 sero-fibrinous exudation, and by the fact that few pneumococci 



Fig. 61. — Capsulated pneumococcus in Mood taken from the heart 

 of a rabbit, dead after inoculation with pneumonic sputum. 



Dried film, fixed with corrosive sublimate. Stained with carbol- 

 fuchsin and partly decolorised, x 1000. 



are found in the blood stream. Intra-pulmonary injection in 

 sheep is followed by a typical pneumonia, which is generally 

 fatal. The dog is still more immune ; in it also intra-pulmonary 

 injection is followed by a fibrinous pneumonia, which is only 

 sometimes fatal. Inoculation by inhalation appears only to 

 have been performed in the susceptible mouse and rabbit ; here 

 also septicaemia resulted. By intratracheal inoculation in dogs 

 Lamar and Meltzer have produced a fibrinous pneumonia 

 pathologically similar to what occurs in man. 



