214 STRONG, CROWELL, AND TEAGUE. 



tained in the bronchi, as well as very large numbers of bacilli. 

 The distribution of the bacilli about the bronchioles has already 

 been described. 



The condition of the lung alveoli in the early stage of the 

 disease varies in different areas. The septa have already been 

 referred to as engorged and the alveoli about the bronchi as 

 filled with bacilli. The alveolar epithelium is swollen and fre- 

 quently desquamated in the form of large cells often containing 

 abundant pigment. The contents of the alveoli consist of a 

 few of these desquamated cells, serum, bacilli, and an occasional 

 leucocyte or red blood-cell. 



The pleura may be the seat of a slight fibrinous exudate, and 

 small haemorrhages from the vessels may have occurred. 



As the process passes on to the later stages of the disease, 

 the added features are those of exudation and more extensive 

 haemorrhages. 



The exudation consists in the passage into the alveoli of red 

 blood-cells and leucocytes, the stage where the red cells pre- 

 dominate probably preceding that of the mixed red and white 

 exudate, so that a red and a white stage can be differentiated. 

 But in no case does the latter condition proceed so far as in 

 the ordinary pneumonia due to Diplococcus pneumonise and the 

 leucocytes are never so abundant. That is to say, there, is 

 not a pure white stage, as a good proportion of red cells is 

 always present and the red appearance of the lung is also more 

 prominent on account of the frequency of haemorrhages which 

 may be small or involve a large portion of the lung. The leuco- 

 cytes are chiefly of the polymorphonuclear neutrophile type, 

 although some mononuclear cells are present. Few, if any, 

 eosinophiles are present in the exudate. Fragmentation of the 

 nuclei of the leucocytes is not infrequent. A peculiarity of the 

 leucocytes when seen under high magnification is that they are 

 very frequently surrounded by a clear zone. The possibility of 

 specific staining for fat was precluded by the method of pres- 

 ervation of the tissues. Phagocytosis was seldom observed. 



The presence of fibrin in the exudate is an unusual occurrence, 

 and in those cases where careful staining showed it to be pres- 

 ent, the amount was in no way comparable to the amount found 

 in ordinary pneumococcus pneumonia and when present was 

 only at the immediate periphery of the alveoli in the neighbor- 

 hood of the vessels. 



In the later stages of the disease, the bacteria are very 

 numerous and here, in contrast to what was described in the 



