248 



THE TISSUES. 



cheek and lips being its most common seat. On the skin it is gene- 

 rally a hard, well-defined tumor, irregularly nodulated, and covered 

 with minute watery papillae. On a mucous surface it appears as a 

 cauliflower-like growth, more or less red from vascular injection, 

 variously consistent, and easily separated into parts by pressure. In 

 either case the papillas and the epithelium covering them become 

 greatly hypertrophied ; the corium and areolar tissue also becoming 



Fig. 154. 



Section of epithelial cancer of the cheek, a. Epidermic scales, and fusiform cells and fibres on 

 the external surface. 6. Group of epidermic scales, c. Areolar tissue of the corium. d. Cancer- 

 cells in the latter tissue. (Bennett.) 



converted into a fibroid substance. Fig. 154 shows the microscopic 

 structure of an epithelial cancer of the cheek. 



4. New formations of epithelium are common in certain patholo- 

 gical cysts. A very delicate ciliated epithelium has been found on 



Fig. 155. 



Oidium albicans. a. A mass of epithelial cells covered with the granular matrix of the fungus 

 (6), from which a luxurious growth of mucedinous filaments (c) proceeds. Magnified 350 diameters. 

 (Kolliker.) 



