400 THE INHABITANTS OF THE SEA. 



Who can explain the instinct which prompts the birds to glue 

 their nests to the high dark vaults of those deep, and apparently 

 so inaccessible, caverns ? Did they expect to find them a safe 

 retreat from the persecutions of man? Then surely their hopes 

 were vain, for where is the refuge to which his insatiable avidity 

 cannot find the way? At the cavern of Gua-gede, the brink 

 of the precipitous coast lies eighty feet above the level of the sea at 

 ebb-tide ; the wall first bends inwards, and then, at a height of 

 twenty-five feet from the sea, throws 6ut a projecting ledge which 

 is of great use to the nest-gatherers, serving as a support for a 

 rotang ladder let down from the cliff. The roof of the cavern's 

 mouth lies only ten feet above the sea, which, even at ebb-tide, 

 completely covers the floor of the cave, while at flood-tide the 

 opening of the vast marine grotto is entirely closed by every wave 

 that rolls against it. To penetrate into the interior is thus only 

 possible at low water, and during very tranquil weather ; and even 

 then it could not be done, if the rugged roof were not perforated 

 and jagged in every direction. The boldest and strongest of the 

 nest-gatherers wedges himself firmly in the hollows, or clings to 

 "the projecting stones, while he fastens rotang ropes to them, which 

 then depend four or five feet from the roof. To the lower ends of 

 these ropes long rotang cables are attached, so that the whole forms 

 :a kind of suspension bridge throughout the entire length of the 

 cavern, alternately falling and rising with its inequalities. The 

 cave is 100 feet broad and 150 long as far as its deepest recesses. 

 If we justly admire the intrepidity of the St. Kildans, who, let 

 down by a rope from the high level of their rocky birthplace, 

 remain suspended over a boisterous sea, we must needs also pay a 

 tribute of praise to the boldness of the Javanese nest-gatherers. 

 Before preparing their ladders for the plucking of the birds' nests, 

 they first offer solemn prayers to the goddess of the south-coast, 

 and sometimes deposit gifts on the tomb where the first dis- 

 coverer of the caverns and their treasures is said to repose. 

 Thus in all zones and in every stage of civilisation, man is 

 • directed by an inward voice to seek the protection of the invisible 

 powers when about to engage in a great and perilous undertaking. 



As I have already mentioned, the Salangana builds her nest of 



■sea-weeds, which she softens in her stomach and then disgorges. 



During its construction new layers, which soon grow hard in 



"the air, are continually deposited on the margin, until it has 



