550 SHINICHI MATSUMOTO 



tially the same as on the endothehal surface. The advancing 

 edge of the growth was composed of a very dehcate sheet of 

 protoplasm, showing amoeboid mo^'ement, with numerous 

 branching hyaline pseudopodia. When the delicate membrane 

 spread out to an extreme degree, it resulted in the breaking up of 

 the sheet into isolated masses. 



In a small percentage of the cultures the spreading of cells over 

 the outer epithelial surface of the cornea (fig. 1, E') as well as 

 along the lower surface of the culture medium (fig. 1, S) was 

 noted. 



The elements of the connective tissue showed neither active 

 growth nor movement. The study of the lymphocytes found in 

 the corneal tissue needs special investigation. 



2. Movement of the epithelium cultivated in serum 



Generally, the cornea cultivated in serum showed some details 

 of cell movement, different from those noted in plasma cultures. 

 No amoeboid migration of the cells into the medium took place. 

 During the first and second hours, the cells of the edges became 

 clear and round, sometimes even swollen in appearance; they soon 

 started to move. 



The most striking and constant phenomenon noted in the use 

 of serum was the spreading out of epithelium over the tissue 

 itself, especially on the endothelial surface. The epithelial rim 

 extended usually parallel with the cut edges, showing amoeboid 

 movement on the advancing border. The rapidity of spreading 

 out of cells was sometimes quite remarkable. In a small per- 

 centage of the cultures, movement of cells was also observed on 

 the original outer epithelial surface of the cornea. 



If single cells or a part of the rim were in contact with the cover- 

 glass, they clung to it and spread over the surface of the glass with 

 marked activity. The boundaries of individual cells were often 

 hard to distinguish under the microscope. When such prepara- 

 tions are properly impregnated with silver nitrate (Lewis and 

 Lewis, '12) the intercellular spaces can be clearly demonstrated 

 (fig. 3). When the delicate membrane had extended to the 



