PATHOLOGY. 215 



earlier cases, they are in greatest number about the medium- 

 sized vessels and can also be seen in the blood contained within 

 the vessels. They are also present in large numbers imme- 

 diately beneath the pleura and in the fibrinous exudate which 

 always covers the pleura over a consolidated area. Where sec- 

 tions were taken through the interlobar septa, the presence of a 

 leucocytic exudate can be seen in the groove between the pleural 

 surfaces. (See Plates XIII to XVII illustrating histological 

 changes.) 



The bronchi. — (See Plate VIII.) The mucous membrane of 

 the bronchi was in every case of a bright-red color which 

 varied in the different instances only in intensity. Often in the 

 bronchi near the bifurcation, the deeper red portions appeared 

 as closely placed, parallel, longitudinal stripes in the bronchial 

 wall. The bronchi contained a red, frothy, bloody serous fluid 

 or more rarely a reddish mucus exudate. The yellow or whitish 

 muco-purulent exudate frequently seen in cases of catarrhal 

 bronchitis or in other forms of pneumonia was never observed, 

 nor were fibrinous plugs encountered. In one case in which 

 the lesions in the lung as well as the changes in the other 

 organs were not very far advanced, the diagnosis of primary 

 lung infection with plague bacilli was suggested from this con- 

 dition in the bronchi and the character of the exudate. This 

 diagnosis was confirmed by bacteriological examination. 



Pharynx, larynx, and trachea. — (See Plate XL) The anterior 

 surface of the tongue was usually coated with a brown, buff, 

 or pinkish-gray layer. The papillae at the base of the tongue 

 and the lymphoid follicles here and on the posterior wall of the 

 pharynx were swollen. The tonsils were in every instance of 

 about normal size or slightly swollen. On cut section the surface 

 was usually reddish or reddish gray and in a few instances bluish 

 in color. In only one case were there small areas of necrosis and 

 haemorrhages in the tonsil. The mucous membrane of the mouth 

 and throat over the base of the tongue, uvula, tonsils, and adjacent 

 structures was in all cases somewhat swollen and generally ap- 

 peared of a more or less congested, dark-red color or in a few 

 instances of a reddish-purple hue. From the pharynx to the 

 larynx the mucous membrane as a rule gradually assumed a 

 brighter red color. Over the epiglottis, vocal cords, cartilages, 

 and whole larynx it was generally markedly hypersemic and red 

 in color, but in a few instances of a whitish-pink or pink hue. 

 When the color was not bright red the injected vessels could be 

 seen more plainly upon the pink background just described. The 



