18 TRANSACTIONS OF THE [ocr. 13, 
Evidence of Subsidence and Elevation. 
The facts bearing on the question of subsidence and elevation 
have already been given, but it may be worth while to briefly 
review them and give my inferences. 
The caves and old beaches now above the sea plainly show 
where the level of the water formerly was. The section at. 
Fresh Creek proves, as do the other cases of elevated corals, that 
the island has been elevated. As the formation on top of the 
corals at Fresh Creek is Aiolian, it follows that it could have 
been deposited only above water; and as the caves and old beaches 
are at least thirty feet above the sea-level and in the Aolian 
formation, they could not have been formed until the islands had 
subsided. Hence we are justified in assuming that at some pre- 
vious time in their history the islands were at about the same 
level as now. ‘Then followed a period of subsidence of at least 
thirty feet, during which the caves and old shore lines were 
formed. After this subsidence the islands were elevated to 
about their present position. It only remains to sum up the 
facts that bear on the question of the most recent movement in 
the Bahamas. 
The fact that on the west coast of Andros, where the slope 
seaward is so exceedingly slight, the soft, calcareous mud grows 
gradually harder and harder as we go inland, indicates to my 
mind that the island has been recently rising; for if it were sub- 
siding or had recently subsided, we may suppose that time 
enough would have elapsed since its elevation to allow the calca- 
reous deposit to harden into rock, and then, as the subsidence 
took place, the surface at the edge of the water would be hard 
rock, which would finally probably extend under the water as 
the latter encroached on the land. The depth, close to the 
shore, of the fine calcareous deposit also points to elevation, for 
in it I ran a pole nine feet. How much deeper it was I had no 
means of determining, owing to the length of the pole. Now, 
had subsidence been taking place, should we find this depth of 
calcareous mud close to the shore? It is perhaps possible, and 
it might be claimed that the greater the subsidence the greater 
would be the depth of the mud ; but by the time that nine feet 
of sediment had been laid down it is reasonable to suppose that 
the mud on the shore would have hardened, and then should we 
not find the water washing against a rocky shore ? 
As we approach the west side of Andros from the interior the 
pines grow smaller and smaller, and the forest is often prolonged 
into points that run out in the swash and are composed of 
young and vigorous trees. ‘There are also in the swash small 
