nt 



Mediterranean, filled up by successive allu- 

 vions. It may be easily conceived, that at the 

 mouth of all great rivers, where the velocity of 

 the stream suddenly diminishes, a bank, an is- 

 land, a deposition of substances which cannot be 

 carried on farther, is formed. It may also be 

 conceived, that the river, obliged to flow round 

 this new bank, divides itself into two branches ; 

 and that the accumulating earth, finding a point 

 of support at the summit of the delta, extends 

 farther and farther, widening these branches*. 

 What takes place at the first bifurcation may be 

 effected in each partial channel ; so that by the 

 same processes, nature may form a labyrinth of 

 small bifurcated channels, which are filled up or 

 grow deeper in the lapse of ages, according to 

 the force and direction of the waters. The 

 principal trunk of the Oroonoko has no doubt in 

 this manner divided itself, twenty-five leagues 

 west of the Boca de Navies, into two branches, 

 those of the Zacupana and Imataca. The net- 

 work of less considerable branches which the 

 rivers ends toward the north, and the mouths of 

 which bear the name of bocas chicas (little mouths), 

 appears to be a phenomenon entirely similar to 

 that of the deltas of tributary streams^-. When 



* Girard f sur la bailee d'Egypte, p. 56. 

 + On the deltas of tributary streams opposed to the oceanic 

 deltas, see above, chap, xxiii, p. 466. 

 VOL. V. 3 A 



