Dec. 1850. SHIFTING OF COURSE OF MEGNA RIVER. PEAT. 341 



on the progression westwards of the Burrampooter (see 

 p. 253) were confirmed by the fact that the Megna also is 

 gradually moving in that direction, leaving much dry 

 land on the Noacolly side, and forming islands opposite 

 that coast ; whilst it encroaches on the Sunderbunds, 

 and is cutting away the islands in that direction. This 

 advance of the fresh waters amongst the Sunderbunds is 

 destructive to the vegetation of the latter, which requires 

 salt ; and if the Megna continues its slow course west- 

 wards, the obliteration of thousands of square miles of a 

 very peculiar flora, and the extinction of many species of 

 plants and animals that exist nowhere else, may ensue. 

 In ordinary cases these plants, &c, would take up their 

 abode on the east coast, as they were driven from the west ; 

 but such might not be the case in this delta ; for the 

 sweeping tides of the east coast prevent any such vegeta- 

 tion establishing itself there, and the mud which the eastern 

 rivers carry down, becomes a caking dry soil, un suited to 

 the germination of seeds. 



On our arrival at Calcutta in the following February, 

 Dr. Falconer showed us specimens of very modern peat, 

 dug out of the banks of the Hoogly a few feet below 

 the surface of the soil, in which were seeds of the 

 Euryale ferox : * this plant is not now known to be found 

 nearer than Dacca (sixty miles north-east, see p. 255), and 

 indicates a very different state of the surface at Calcutta at 

 the date of its deposition than that which exists now, and 

 also shows that the estuary was then much fresher. 



The main land of Noacolly is gradually extending 

 seawards, and has advanced four miles within twenty- 



* This peat Dr. Falconer also found to contain bones of birds and fish, 

 seeds of Cucumis Madraspatana and another Cucurbitaceous plant, leaves of 

 Saccharum Sara and Ficus cordifolia. Specks of some glistening substance were 

 scattered through the mass, apparently incipient carbonisation of the peat. 



