112 



iindci- imicli more imiloini conditions Ihan would have 

 lu'cn Ihc i-asc if I he c-i-lls were allowed lo f^n-ow end)edded in 

 Ihe elot The eondilions on the nioisl snrlaee are much 

 llu' same as those under wliieii the epillieliai cells norm- 

 all\ ^I'ow in tin- body. 



\Tf 



t 



# 



« 







> -t- 



m 





Fig. 11. 



Stained culture of epithelial cells 2 months old. ;< 1,425. 



From The Journ. of Exp. Med. 1922, XXXV. 367. 



The characlerislics of surface cultures of epithelium are 

 the following: The cells form big solid sheets or membranes, 

 mostly in one layer only. (Fig. 9.) The cells are polygonal 

 and foi-m a pavement. (Fig. 10.) Between the individual 



