134 MOUNT EGMONT. [PART I. 



with shrubs ; in others the loose sand has here and 

 there acquired some solidity from the roots and fibres 

 of a running carex, which is the first preparatory step 

 to its becoming fit for other plants. In several 

 places behind these sand-hills lagoons of fresh water 

 are found, which abound with ducks, but contain no 

 other fish than some large eels, in order to catch 

 which the natives formerly cut through the sand- 

 hills and emptied the lagoon. Round these lagoons 

 the vegetation was very rich, and amongst the shrubs 

 was the handsome Apeiba australis, which I observed 

 here for the first time. 



Towards Sugarloaf Point large boulders, all 

 consisting of volcanic rocks of apparently an old 

 date, as basalts, greenstones, trachyte, augitic rock, 

 &c., were cemented together into an extremely solid 

 conglomerate, which appeared to extend like a stream 

 of lava from Mount Egmont into the sea, but can- 

 not be traced far. Where the water washes these 

 rocks the conglomerate is peculiarly hard, and this 

 is caused by a chemical action of the salt water, 

 either on the particles of the iron pyrites, with which 

 several of the rocks abound, and which often cover 

 the pebbles with a metallic crust, or else on the 

 black titanic iron-sand which is found on the beach. 

 In some places this chemical action is accompanied 

 by the development of a good deal of heat, which is 

 perceived where, at the retiring tide, the sea leaves 

 ponds of water between the rocks. A strong smell of 

 sulphuretted hydrogen gas may also be observed about 



