25] RATE OF REGEXERATION—ZELENY 25 



eration there is again essential similarity between the old tissue and the 

 new tissue levels. 



7. The result strengthens the view that the rate of regeneration is 

 controlled in large part by factors not inherent in the character or con- 

 dition of the cells near the cut surface. 



8. In the case of the earliest stages, those in which there is cell 

 migration but no cell division, there is some evidence that the rate of 

 regeneration may be greater from new than from old tissue. 



