122 IOWA STUDIES IN NATURAL HISTORY 
sages in the limestone, none of them long or large, except per- 
haps for one or two caves; Coles’ cave on the Walkes Spring 
Estate is the largest and may be explored for some distance 
underground; The Manning eave is another example; human 
excavation is responsible for the greater part of the rock re- 
moval from this interesting cavern. Limestone sinks are not 
uncommon and these depressions are in some eases nearly filled 
with water during the wet season and a few of them never go 
quite dry. 
The seaward edges of some of the higher terraces are deeply 
gashed by vertical box-like canyons a few hundred yards in 
length ; a good example was seen in the vicinity of Mt. Brevitor 
on the Whitehall Estate. A sea cave on the slope of this hill at 
an elevation of 381 feet above the sea and 100 feet above the 
ecanyon-cut terrace at its foot is 75-100 feet in extent and 30-40 
feet high inside. Other smaller caves are common along this 
bold scarp. The fauna and flora in them is of great interest. A 
maidenhair fern so delicate that the first touch of sunshine out- 
side wilted it as if scorched and some pale whistling frogs and 
numerous land snails chiefly Subulina octona were the com- 
monest. 
The residual clay and marl formed from the decay of the 
coral limestone makes a very good soil and where it is fairly 
thick above the mantle rock it holds moisture well. The fact 
that this soil has been extensively cultivated for centuries, grow- 
ing sugar-cane most of the time attests its fertility. 
The roads of the islands are fairly good. Many automobiles 
make for their upkeep. Their dazzling whiteness is due to the 
use of the limestone into which, especially along the edges of the 
terraces, they are cut and with which they are constantly 
mended. 
The coral limestone is quarried by hand in the most primitive 
way, being cut with simple tools into blocks of various sizes, the 
commonest size is 1144x1x2 feet. Many of the finest buildings 
in Bridgetown are constructed of the local stone and it makes 
rather pleasant appearing structures and is quite durable as it 
seems to harden upon exposure to the weather; the Public 
Buildings, the Cable Office, Sir Gilbert Carter’s home, ete. are 
some examples. There are many fairly good sized quarries in 
