20 



THE TONER LECTURES, 



of epithelial tissues is effected^ not by cell multiplication^ hut 

 by these wandering corpuscles becoming fixed and developing 

 into epithelial ceils, we shall readily understand the signifi- 

 cance of this circumstance. But be this as it may I cannot 

 doubt that, in many cases at least, l^esides the continuous epi- 

 thelial outgrowth, however that may be effected, a portion of 

 the small-celled brood accumulating in the lymphatic passages 



Fig. 2, 



Two wandering corpuscles among the epithelial cells of an epithelial 



cancer. From the same preparation as photo-micrograph 



Ko. 29. Magnified GOO diameters. 



undergoes a transformation into epithelial forms, and thus 

 contributes its share to the growth of the cancer. (Two pho- 

 tographs, Nos. 28 and 29, shown.) 



Before passing from this part of the subject I desire to call 

 your attention to a couple of photographs taken from an epithe- 

 lial cancer of the lip, which illustrate the manner in which such 

 growths, when they penetrate deeply, invade the voluntaiy mus- 

 cles. In such cases, if the section is taken transversely to the 



I 



