HEW PHYTOIiOGIST. 
Vol. 4. Nos. 2 & 
March 30TH, 1905. 
SKETCHES OF VEGETATION AT HOME 
AND ABROAD. 
I.—The Flora of the Ceylon Littoral. 
By A. G. Tansley 
and 
F. E. Fritsch. 
(Continued from />. 17). 
[Plate I. and Text Figs. 8—16] 
Part II. —-The Tidal Mud Formations. 
HE formations that fall under this heading inhabit the 
1 tracts of mud, covered by water at high tide and left 
bare at the ebb, which are found on all flat coasts where great 
quantities of fine-grained alluvium are deposited. The coherent 
mud offers a very different substratum for vegetation from that 
afforded by loose sand, and enables plants to obtain a footing and 
form a permanent vegetation between tide-marks, a feat impossible 
to them in the case of sand, which is constantly being moved about 
by the water. The great enemy of tidal mud-vegetation is wave- 
erosion. Where this is constant plants cannot of course maintain 
themselves, being continuously liable to have their soil and them¬ 
selves carried bodily away. On coasts and in estuaries exposed to 
vigorous tidal action, the processes of erosion and deposition of 
mud, of uprooting and re-colonisation by the plants can be studied 
in all its phases; and every case is to be met with from situations 
where plants can never establish themselves owing to a continuous 
tidal scour, through others in which alternate erosion and deposition 
allow of a transient vegetation only, to the more protected areas 
where the force of the tide is reduced to a minimum, and the mud 
