13 



I.Ari':i! STAGES U1-" GADOIDS 



x: 



24 



21 



. 18 



15 

 12 



<u 



E 9 



13 



10 20 30 40 50 60 70 80 90 loa 



Fig. 12. The corresponding curve; April — June. 





\.-.: 



70 



^50 

 in 

 tZ 



o 



c_ 

 <u 30 



E 

 ^20 



10 20 30 40 50 60 70 80 90 100 



Fig. 13. The corresponding cui-ve; July — September. 



