121 



a discussion about the tubule formation being the result 

 of the action of contaminating fibroblasts (D r c \v) '•'>'). 



As a whole the epithelial cultures are easily multiplied. 

 Some of them are more difficult to multiply, namely, those 





Fig. 17. 

 Experiment 25970 — 2. The individual cells appear spindle-shaped and flat. 



■; about 200. 

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



which form the tubules; they are often small and can 

 hardly be extirpated entireh' from the clot. The surface 

 grown epithelium sometimes gives trouble; after extirpation 

 it usually contracts, as docs a drop of mucus, and is diffi- 

 cult to replace on the surface of the clot in such a way 



*»A»*' 



