- M 



_ >t 

 'I 



I 



I 



i 



I 

 i 



\ 



s^ ^ 



' * \ K ,' / 



B 



*'**%N 





-I I I l_ 



I I I I 1_ 



-I I I u 



-I I I I 



DAYS 



Fig. 4. Change in component values in time — experiment 4, 

 Symbols are the same as for figure 2. 



144 



