473 CORAL REEFS AND VOLCANOES, [chap. xx. 



oilier. Taking into consideration the proofs of recent 

 elevation both on the fringed coasts and oh some others 

 (for instance in South America) where there are no reefs, 

 we are led to conclude that the great continents are for 

 the most part rising areas ; and from the nature of the 

 coral-reefs, that the central parts of the great oceans are 

 sinking areas. The East Indian Archipelago, the most 

 broken land in the world, is in most parts an area of 

 elevation, but surrounded and penetrated, probably in more 

 lines than one, by narrow areas of subsidence. 



I have marked with vermilion spots all the many known 

 active volcanoes within the limits of this same map. Their 

 entire absence from every one of the great subsiding areas, 

 coloured either pale or dark blue, is most striking ; and not 

 less so is the coincidence of the chief volcanic chains with 

 the parts coloured red, which we are led to conclude have 

 either long remained stationary, or more generally have 

 been recently upraised. Although a few of the vermilion 

 spots occur within no great distance of single circles 

 tinted blue, yet not one single active volcano is situated 

 within several hundred miles of an archipelago, or even 

 small group of atolls. It is, therefore, a striking fact, that 

 in the Friendly Archipelago, which consists of a group of 

 atolls upheaved and since partially worn down, two volcanoes, 

 and perhaps more, are historically known to have been in 

 action. On the other hand, although most of the islands 

 in the Pacific which are encircled by barrier-reefs, are of 

 volcanic origin, often with the remnants of craters still 

 distinguishable, not one of them is known to have ever 

 been in eruption. Hence in these cases it would appear, 

 that volcanoes burst forth into action and become extin- 

 guished on the same spots, accordingly as elevatory 

 or subsiding movements prevail there. Numberless facts 

 could be adduced to prove that upraised organic remains are 

 common wherever there are active volcanoes ; but until it 

 could be shown that in areas of subsidence, volcanoes were 

 either absent or inactive, the inference, however probable 

 in itself, that their distribution depended on the rising or 

 falling of the earth's surface, would have been hazardous. 

 But now, I think, we may freely admit this important 

 deduction. 



Taking a final view of the map, and bearing in mind 

 the statements made with respect to the upraised organic 

 remains, we must feel astonished at the vastness of (he 



