CARTER : THE EVOLUTION OF THE DON RIVER-SYSTEM. 399 
A*^ I. 
•■ I " «/ y 
■■■■) 
— ■ — — 
"\. m. 
Fig. 4. 
DIAGRAM SHOWING THE STEPS SUGGESTED BY WHICH THE CAPTURE OF TIEE 
PEXISTOXE DON BY A FEEDER OF THE SHEAF WAS EFFECTED 
AND THE CONVOLUTIONS AT WORTLEY WERE PRODUCED. 
The Capturing River is represented by the double line, the Captured River by the single line. 
