MORBID ANATOMY 



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light, glassy and pearl gray by reflected light, and are sur- 

 rounded by a congested or a hemorrhagic ring. The center of 

 the nodules shows a pale yellow point in consequence of casea- 

 tion and disintegration of the innermost cells. These nodules 

 are of different sizes, of varying numbers, and of different 

 ages. The formation of a capsule by a connective tissue mem- 

 brane is induced by a reactive inflammation in the tissue sur- 

 rounding the nodule. The nodules may be of an embolic 



Fig. 27. Drawing of a horse's lung containing glanders nodules {a). 

 They appear on both the pleural and cut surfaces. 



origin, situated principally in the periphery of the lung, their 

 structure being the same as that of the nodules in the nasal 

 mucosa. Sometimes the lung nodules represent lobular pneu- 

 monic foci, in which the alveoli are filled with red and white 

 blood corpuscles and with desquamated epithelium of the 

 lungs. Central disintegration occurs very early. These areas 

 are surrounded by a membrane resulting from a reactive in- 

 flammation which manifests itself and out of which a connec- 

 tive tissue capsule develops later on. There are two theories 

 concerning the structure of the early nodules. One is, that 

 the first cells are epithelial in nature, thus closely resembling 



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