32 Tahiti. paet i. 



filled in the manner here described ; and it is difficult 

 to imagine the causes which determined the earthy 

 mineral to sink from its gravity to the bottom of the 

 cells, and the crystalline mineral to adhere in a coating 

 of equal thickness round the sides of the cells. 



The basaltic strata on the sides of the valley are 

 gently inclined seaward, and I nowhere observed any 

 sign of disturbance ; the strata are separated from each 

 other by thick, compact beds of conglomerate, in which 

 the fragments are large, some being rounded, but most 

 angular. From the character of these beds, from the 

 compact and crystalline condition of most of the lavas, 

 and from the nature of the infiltrated minerals, I was 

 led to conjecture that they had originally flowed beneath 

 the sea. This conclusion agrees with the fact that the 

 Rev. W. Ellis found marine remains at a considerable 

 height, which he believes were interstratified with 

 volcanic matter ; as is likewise described to be the case 

 by Messrs. Tyerman and Bennett at Huaheine, an island 

 in this same archipelago. Mr. Stutchbury also dis- 

 covered near the summit of one of the loftiest moun- 

 tains of Tahiti, at the height of several thousand feet, 

 a stratum of semi-fossil coral. None of these remains 

 have been specifically examined. On the coast, where 

 masses of coral rock would have afforded the clearest evi- 

 dence, I looked in vain for any signs of recent elevation. 

 For references to the above authorities, and for more 

 detailed reasons for not believing that Tahiti has been 

 recently elevated, I must refer to my volume on the 

 1 Structure and Distribution of Coral Reefs ' (p. 188 of 

 the 1st edit., or p. 182 of the 2nd. edit.). 



filled up horizontally with quartz and chalcedony. The upper 

 halves of these cavities are often filled by layers, which follow each 

 irregularity of the surface, and by little depending stalactites of the 

 same siliceous substances. 



