Diphtheritic Membrane and the Croupous Cast. 



83 



spread out with needles ; the columnar epithelium retains its ciha ; 

 each cell being filled with clear protoplasmic and nucleated con- 

 tents. It is, therefore, highly probable that these casts are not 

 long retained, but are rather thrown off soon after their forma- 

 tion. Fungus spores are rarely found in these films, which ap- 

 pear to partake of the nature of an excessive cell prohferation of 

 the epithelial surface rather than of a transudation, or true exuda- 

 tion. Although such casts difier a good deal in colour and con- 

 sistency, connective or fibrous tissue never enters into their 

 composition ; but the transparent mucus often exhibits the stria- 

 tions or wavy lines peculiar to this material. 



Such casts are thrown oflf from the intestinal canal, and pre- 



FiG. 2. 



+ J50 



Section of Croupous Cast. 



a. Homogeneous matrix, in which altered epithelium granular and fatty 

 matters are entangled. 6. Columnar epithelium, with cilia retained, c. Detached 

 epithelium fat and mucous corpuscles. 



sent similar appearances. Fig. 2 represents a drawing made from 

 a croupous cast, and stained with carmine. 



The several examinations that I have made clearly show that 



VOL. X. H 



