540 



TUMORS. 



thelia of the lymph-vessels, without, however, throwing light upon this ques- 

 tion. Recently, also, A. Classen has endeavored to include the " migrating 

 cells " in the production of cancer, forgetting, evidently, the fact that 

 "migrating cells " are always elements in the stage of indifference ; that epi- 

 thelia, if fully developed, are not possessed of the capacity of migration, and 

 that no proof has yet been furnished of a new formation of tissue from wan- 

 dering corpuscles. 



The subjects of my researches were cancers which had been removed from 

 the right parotid region, from the skin of the face, from the female breast, 

 and from the liver. The characteristic feature common to all cancers is the 



FIG. 224. CANCER OF THE SKIN OF THE PAROTID REGION. 



CE, large, nucleated cancer epithelia, partly separated from each other by elastic libers, 

 E; C, unchanged fibrous connective tissue of the derma of the skin. Magnified 600 

 diameters. 



epithelial new formation, the epithelial bodies, however, varying greatly in 

 size. The largest I saw were in the cancer of the parotid region. (See Fig. 

 224.) 



The cancer epithelia represented polygonal bodies, separated from each 

 other by narrow rims of cement-substance having a ledge-like appearance and 

 traversed by delicate spokes. Sometimes I saw the peg-like or alveolar for- 



