127 



The epithelial cells do not j){)ssess this ability lo such an 

 extent. When I lie latter grow in vitro Ihey seem to retain 

 their flat cell shapes. They li((uefy the culture medium to a 

 great extent. It is often observed how the fragment of 

 epithelial cells makes a concavity in the clot when they 





Fig. 21. 



Same section as Fig. 20. X 120. 



From The Journ. of Exp. Med. 1922, XXXVl, 285. 



ai*e cultivated on the siu'face. They simply grow in sheets 

 consisting of cells in one layer and liquefy the medium 

 during the growth so that a large amount of fluid is found 

 covering the culture after fourty-eight . hours incubation. 



