271 



I'liu'iK'c on the rale ol' orowih and on Ihc maliffnily of (lie 

 sarcoma cells. 



Numcrons problems arc being worked out al Ihe present 

 lime to investigate the l)ehaviour of sarcoma cells towards 

 normal tissue cells; and as il lias often \)vvn observed tbat 

 some chickens are primarily immune to inoculation of ttie 

 Rous sarcoma, it is my ho])e by means of the tissue 

 cultivation method to discover whether this immunity is 

 humeral or cellular. 



