THE MICROSCOPE IN DIAGNOSIS. 295 



is similar to warts or pointed condylomata ; dcatricfal, 

 occurring usually in the skin of the face of old people as 

 a superficial slowly growing cancer presenting a cicatri- 

 cial contraction of the stroma from gradual retrogression 

 and reabsorption of the cells ; and the mucous cancroid, 

 or cylindroma, characterized by cylindrical or arborescent 

 masses of mucous substance. 



The term cylindrical epithelioma has been given to those 

 forms which appear on mucous membranes with columnar 

 or cylindric epithelium. The tumors present the same 

 epithelial elements as the tissues whence they grow. The 

 walls of the alveoli show columnar epithelium, so that 

 the distinction between such tumors and simple adenom- 

 ata is very difficult. A variety of this form occurs as a 

 villous growth on mucous membranes, as the bladder, 

 uterus (cauliflower excrescence), and stomach. 



CHAPTER XIV. 



THE MICROSCOPE IN DIAGNOSIS. 



IN diagnosis the microscopical observer is necessarily 

 confined to an examination of the various fluids and dis- 

 charges of the body. Dr. Pritcbard's microscope for ex- 

 amining the circulation of blood in the frsenum of the 

 human tongue, described by Dr. Beale, is an ingenious 

 attempt to investigate the actual condition of the living 

 subject, and indicates a direction which may hereafter be 

 profitably pursued, but as yet is too refined for the pur- 

 poses of the practical student. 



I. THE BLOOD IN DISEASE. 



The normal structure of blood has been sufficiently de- 

 scribed at page 186. It remains now to point out briefly 



