Tee eee ee Se ee ee 
672 
than it would be from darker earth; it is also true that the vegetation 
overhanging the edge of the beach would have its transpiration increased 
by the increase in the temperature of the leaf because of the reflection 
from the water at high tide. 
Schimper *’ calls attention to the fact that some beach plants are 
among the trees most commonly cultivated in the Tropics. My observa- 
tion shows that not only is this true but also that many sea-beach plants 
are present in certain inland habitats and that in most instances such 
plants are more vigorous than individuals of the same species growing on 
the shore. 
On the Reserve, isolated trees of such coastal species as Hrythrina 
indica and Pongamia glabra grow in the forest along streams consider- 
ably above the influence of sea water and these trees growing inland 
are more vigorous than those growing on the coast. Cycas circinalis, 
a common plant of the coastal region in many parts of the Philippines, 
although not on the beach at Lamao, was collected from two localities 
at about 900 meters’ altitude. A grove of these trees is situated near 
the top of Limay peak and the individuals there are more thrifty than 
any I have seen on the beach. Ipomoea pes-capre and Spinifix squar- 
rosus are not confined to the strand, but also occupy positions beyond the 
influence of the sea. Outside the Reserve, the following trees grow both 
on the beach and inland: Casuarina equiselifolia, Terminalva catappa, 
and Erythina indica. Terminalia, Erythina, Caldphyllum inophyllum, 
and Barringtonia speciosa are commonly cultivated in Manila and in 
other places in the Islands. In all instances the most thrifty trees are 
those not situated on the seashore. It is evident that where beach 
plants are propagated inland, they are more thrifty than individuals of 
the same species growing on the beach and that they can not be considered 
zerophilous in nature, though they are xerophytic. Ordinarily, the 
struggle for existence in the better soils is too great for them and hence 
they are driven to the coast, where their plasticity is such as to enable 
them to adapt themselves to the severe conditions imposed. 
It is well known that most of the species common to the seashore have 
fruits adapted for disposal by water currents. The cosmopolitan nature 
of beach plants is to be attributed to this fact. 
2. THE STRAND LYING BELOW HIGH TIDE. 
As the detritus, washed into the sea by rivers reclaims land therefrom, 
bars may be formed and eventually these may be built above the level 
of the sea and in this way lagoons are eventually separated which, for 
a greater or less length of time are kept open by the ebb and flow of tides. 
Mud flats which often are not cut off from the open sea, are formed in 
protected bays or re-entrants, where deltas are in the process of building, 
5 Loc. cit., 91. 
