HISTOLOGY 233. 



Microscopic exainiiiatfon. The nodules were hardened and 

 embedded some in collodion and some in paraffin. Various 

 staining methods were tried, hematoxylin and eosin, carbol- 

 thionine, Gram and lithium carmine with Weigerts fibrin 

 stain. Good results were obtained with all, but the carmine 

 and Weigert gave the most beautiful picture and by this 

 method the fungus was most perfectly demonstrated, the spores 

 and mycelium taking on a deep purple color. The histology 

 was studied largely in sections stained with hematoxylin and 

 eosin. The bronchial epithelium was normal in places, but, 

 for the most part, the columnar cells have been replaced by a 

 sort of membrane, which appears to be made up almost entirely 

 of a felt-work of mycelial, threads. From this membrane 

 hyphce grow out into the lumen of the bronchus, and here, 

 owing no doubt to the supply of air, fruit hyphse arise, with 

 perfect sterigmata and spores. There is no cellular nor other 

 exudate and verj^ little debris. The under surface of this 

 membrane is of looser texture, and contains some cellular in- 

 filtration made up of round cells, leucocytes, proliferated con- 

 nective tissue cells and red blood corpuscles. The adjacent 

 structures are closeh' filled with a cellular infiltration with a 

 quantity' of m^'celium of the same description, this extending 

 to the neighboring alveoli which under low power appear to 

 have preserved their outline but with greater amplification are 

 seen to have lost all their normal structure, showing clumps 

 of homogeneous, irregular masses which stain faintl}- with 

 eosin and are probably of connective tissue origin. 



In these areas the mycelium followed the alveolar wall as 

 a trellis, the tissue seeming to afford no obstacle to its advance. 

 Within the alveoli is a finely granular debris, with some 

 coarser particles, probably the remains of cells. In sections 

 stained with carbol-thionine large numbers of mast cells are 

 seen in the alveolar walls. Bordering these degenerated areas 

 are alveoli which have retained their normal structure and are 

 filled with a network of fibrin holding in its meshes a few 

 cells. In other parts of the sections are areas resembling those 

 just described, but in which all anatomical land marks have 

 been destroyed, so that it is impossible to tell whether or not 

 the spaces seen are bronchi. 



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