ii8 



CICATRIZATION OF WOUNDS 



A certain relationship on general lines could evidently be 

 foreseen a priori. But nothing authorized the prediction that 

 the differences due to age would be more important at the 

 beginning than at the end of life. In other words, it was in 

 no way evident that the plasma of an animal would reflect 



2.0 



10 



/ 23/^567 S9y 



€drb 



FIG. 25. RATE OF GROWTH OF FIBROBLASTS AS A FUNCTION OF THE 

 AGE OF THE ANIMALS FROM WHICH THE SERUM WAS TAKEN 



so exactly the complex variations due to the ageing of a 

 human being. 



It is true that many of the characteristics of cicatrization 

 can be found in tissue- cultures. For instance, the considerable 

 acceleration of cellular proliferation brought about by a lesion. 

 Fischer put this phenomenon in evidence by placing cultures 

 under such conditions that their rate of growth became very 



