160 PATHOLOGY 



tain fibrous plugs. The cut surface of the lung presents 

 a granular, reddish-brown appearance resembling liver 

 tissue, hence the name hepatization. 



Gray Hepatization. In this stage the tissue has 

 changed from reddish-brown to grayish-white in color. 

 The air-cells are filled with leukocytes, the fibrin and 

 red blood-cells having largely disappeared. 



Resolution. In this stage liquefaction of the alveolar 

 contents takes place partially through autolytic diges- 

 tion and partially by mucoid and fatty degeneration. 

 The liquefied mass is expectorated, absorbed, and ex- 

 creted by the kidneys, air again enters the alveoli, and 

 the parts gradually approach the normal. 



Morbid Physiology. Interference with respiratory 

 function is proportionate to the amount of the lung in- 

 volved and the pain and fever present. The absorption 

 of toxins causes profound systemic disturbances, evi- 

 denced by prostration, high temperature, weak heart 

 action and low blood-pressure, and leukocytosis. The 

 diplococcus may enter the blood and give rise to compli- 

 cations in distant organs, as endocarditis, pericarditis, 

 and meningitis. 



DIPHTHERIA 



Definition. An acute infectious and contagious dis- 

 ease due to the Klebs-LorHer bacillus, characterized by 

 a fibrous exudate at the site of infection and constitu- 

 tional symptoms due to toxins produced at the site of 

 the lesion. 



