PATHOLOGY. 205 



well, and patches of haemorrhafire into the alveoli around these engorged 

 vessels are seen scattered about. In a pneumonic area three zones can 

 be made out. At the circumference there is intense engorgement of all 

 vessels including alveolar capillaries, the alveoli are full of blood, and 

 the haemorrhage is so intense that many of the alveolar septa are broken 

 down, entirely absent, or represented by mere shreds. Within the cir- 

 cumference is seen a zone in which the alveoli are intact and are com- 

 pletely filled with well-stained cells, so that there is no interval between 

 the alveolar walls and their contents; and at the centre is one universal 

 mass of similar cells, and the cellular infiltration is so extreme that the 

 walls of the alveoli are scarcely visible. Such is the general arrangement 

 of the pneumonic patch, although there may be alveolar haemorrhage in 

 parts of either the middle or central zone. Under a higher power the 

 alveoli of the circumference are seen to be completely filled with blood 

 corpuscles, and there is scarcely an appearance of fibrin, or none at all ; 

 in the middle zone the alveolar contents consist for the most part of 

 catarrhal epithelium with some white and a few red blood corpuscles, and 

 a little fibrin or none at all, whilst the dense central mass of the cells con- 

 sist of catarrhal epithelium and leucocytes with some granular debris. 

 Thus the pneumonic area has the appearance of very extreme lobular or 

 catarrhal pneumonia. The walls of the bronchial tubes, as well as of 

 the large veins, show great engorgement and there are haemorrhages 

 into the vein walls. Blood and catarrhal cells may be seen in the finer 

 bronchi, but the bronchial mucous membrane is scarcely altered, there being 

 at most a little cellular proliferation. There are the appearances of acute 

 pleurisy over those pneumonic areas which project upon the surface of 

 the lung, with hsemorrhages beneath the pleura. The bronchial glands 

 show engorgement of blood vessels, some haemorrhage into the gland tis- 

 sue and distended lymphatic vessels; but in some cases these conditions 

 are only slightly marked and the glands looked nearly normal." 



Albrecht and Ghon ^ in their report upon bubonic plague describe three 

 cases of primary plague pneumonia. From the study of these cases, they 

 concluded that the primary plague pneumonia represents a typical lobular 

 pneumonia or bronchopneumonia which involves either a single lobe, or 

 several lobes (in some cases bilateral), or an entire lung. 



They further state: On the cut section one can, as a rule, still make 

 out the confluence of the separate infiltrated lobules, since their boundaries 

 can still be partially distinguished. The posterior portions of the lung 

 tissue are most often attacked by the inflammation. It has already been 

 remarked that the primary as well as the secondary plague pneumonias 

 both have a very characteristic and, in this sense, specific appearance, since 

 the finer anatomic picture resembles that of no other inflammatory disease 

 of the lungs with which we are acquainted. Even in the pleura the peculiar 

 conformation and color of such foci is striking. The pleura is either only 

 slightly cloudy, injected to a bright color, and dotted with numerous small 

 haemorrhages, or it is covered with or penetrated by a yellowish, fibrinous, 

 exudative membrane. This fresh pleurisy is, as in every pneumonia, a 

 regular part of the inflammatory process. 



' Ueber die Beulenpest in Bombay im Jahre 1897. K. Akad. d. Wiss. 

 (1898), II. B., 429. 



