LIST OF PLATES Plate Page I. Progressive Underwater Erosion, River Thames 10 II. River Thames, Cross-sections: Long Reach and St. Clement’s Reach ..-..--22 III. Pea Plant growing in a Water-culture Solution, with Extensive Development of Root-system - - - 44 IV. 1. The Scolt Head Dune Massive; 2. Young Dunes, Blakeney Point -.--..--58 V. Dunes Colonized by Carex arenaria and Salix repens, Coxyde, Belgium ....-.-62 VI. Wandering Dunes --------66 VII. Dune Planting at Port Fairy, Victoria 84 VIII. 1. Embryo Psamma Dune at Blakeney Point; 2. Wandering Dune at Southport ------ 86 IX. The Chesil Bank -------96 X. Shingle Plants - -- -- ...-98 XI. Views of Tamarisk Hedge ------- n6 XII. Elevation of Timber Gantry for shutting up River Breach- 140 XIII. Elevation of Typical High Groyne ----- 140 XIV. Boundary between High and Low Salt Marsh - - - 166 XV. Algae as Pioneers on Mud- ------ X72 XVI. Obione portulacoides - -- -- -- - jyg XVII. Clumps of Spartina Townsendii, invading Holes Bay, Poole Harbour, 1912......Frontispiece XVIII. Spartina Townsendii ------- - jg0 XIX. Hummock Development (Bouche d’Erquy, Brittany) - 190 XX. Bouche d’Erquy, Brittany ------- ¡q2 *1