;w 



knowledf^c of Ihc limitations of Iho method among the in- 

 vestigators, it inusl be repeated that to get a thorougli un- 

 derstanding of the pliysiology and patiiology of tissues, it 

 is important not only to Iveep the eells surviving in vitro, 

 but is more important to deal with permanent strains of 

 the various tissue cells in order to operate with more clearly 

 cut experiments, hirst tluii wt' may exj^ect that this method 

 will bring clearness to ilic many mysterious problems, 

 hitherto unassailable because of the complexity of the or- 

 ganism as a whole. 



