125 



together for several |)assaj4cs in Ihe same eiiKiire. Al'ler 

 a lew ])assages Ihe eonneeliNc I issue cells had overgrown 

 the epithelium and the culture looked like an ordinary 

 fibroblast culture. After about seven passages the culture 



■J. -'^iMi^i 



r 



A 



B 



Fig. 19. 



Experiment 1532 — 4. Culture ot fibroblasts and epittieliat celts cultivated 



together, after 48 tiours incubation. Stained with methylene blue. A, fragment 



of a 10 year old strain of fibroblasts; B, fragment of a 2 month old strain 



of epithelium. X about 20. 



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



was fixed and sectioned and stained with Van G i e s o n's 

 stain. The picture which was obtained here was very striking 

 (Fig. 20, 21). In the middle oi the dense connective tissue, 



