i(;() 



rclrMclion ol' [hv l'il)rin clol. In allcmpls lo inninUiin uniform 

 coiulilioiis (lui"inj^ tlic scpaiMlioii ol" Ihc siiinll liMj^niU'iil IVoni 

 llu' mollur ciilliiic. imollicr lcclini(|iii- \v;is (Icxiscd. 



Fig. 33. 



A photograph of the culture illustrated diagramaticaliy in Fig. 32. 



From The Journ. of Exp. Med. 1923, XXXVlll, 671. 



A culliirc was pormillcd lo grow lor al)oiil 20 liours, and 

 then the cover-glass was unsealed and an incision was made 

 in the periphery of the new growth willi an ordinary sliarp 

 calaracl knife, in order lo separate from (lie mother eullure 

 a piece of tissue at the ])eripliery whei'e the cells wei'e rallier 



