4V0 A. E. Verrill — The Bernoulli Islands. 



(i. — Mangrove, Sir am ps. 



When small bays or lagoons are thus formed by the invasion of 



the sea, if they should be sheltered from violent waves, mangroves 

 and black-jack trees take root in the sea water itself, as well as 

 along its borders. By means of the peculiar descending shoots or 

 aerial roots of the former and the ascending shoots from the roots of 

 the latter, a dense thicket or mangrove swamp is soon formed, admir- 

 ably adapted to collecting and retaining dead leaves, mud, and sedi- 

 ment of all kinds, thus gradually increasing the area and fertility of 

 the land. (See plates lxviii, fig. 2, and ixxiv, fig. 1, and Native 

 Trees, Part III, ch. 26, e.) 



Such mangrove swamps, usually of small extent, exist in many 

 places, as at Coney Island, Walsingham, Spanish Point, Tucker's 

 Town, etc. Larger and denser ones may be seen at Hungry Bay, 

 Mangrove Bay, and several other places. 



V. — Caverns and (h'ottoes. 



Among the more interesting of the geological phenomena are the 

 numerous caverns, usually hung with numerous huge stalactites, but 

 sometimes with innumerable small and delicate ones ; and in some 

 places decorated with the most delicate fret-work, or with thin, 

 translucent draperies, of snow-white stalactitic material. 



Some of these caverns are of considerable extent, but the larger 

 ones are generally partly submerged below the level of the sea, so 

 that the floor may be covered with clear sea-water, 10 to 20 feet 

 deep. Sometimes stalagmites can be seen rising up from the bot- 

 tom, beneath the sea water. A large cavern on Tuckers Island,* of 

 this description, had been fitted with pipes for acetylene gas and the 

 proprietor had a boat inside, with which he, like Charon, took his 

 visitors across the dark and mysterious waters. In this cavern the 

 stalactites are of colossal sizes, but they are dark and dull in color, 

 as if finished ages ago, as indeed they doubtless were. 



On the Walsingham place there are several well known caverns. 

 We succeeded in obtaining photographs of two of these. (See plates 

 xc-xcii.) One of them has two entrances and does not contain water, 

 though it is in a depression, not much above sea-level. It is near 

 Thomas Moore's famous Calabash Tree. The stalactites are of large 

 size, but badly smoked by the torches and bonfires of the innumer- 



* Since my visit, this island has been converted into a prison-camp for the 

 Boers, and is not at present accessible to the public. 



