82 THE COEAL REEFS OF THE MALDIVES. 



(Pis. 2, 3), a condition which can hardly be called that of an atoll. Such a 

 state of things seems to indicate that coral reefs and atolls may begin at any 

 point or knoll or ridge or range or summit or flat of a plateau, having the 

 depth at which corals may begin to form, provided its waters have the 

 necessary temperature and the' proper exposure to currents or trades. 

 The surface of the Maldivian plateau consists of a host of such knolls, 

 summits, and ridges of greater or less dimension, upon which have risen the 

 complicated system of islands, faros, reef flats, and atolls with which we have 

 become familiar during our exploration of the Maldives. 



To understand the coral reefs of the Maldives,, we must look upon each 

 ring or faro or islet or island on a reef flat as a thing by itself, just as much 

 entitled to be called an atoll as any of the smaller atolls found in the 

 Pacific, — atolls which only incidentally play a secondary part as reef flats 

 of the outer faces of the groups, but which in spite of their position do not 

 hold to the enclosed water the same relation which the reef flats or land 

 rim of an atoll hold to the enclosed lagoon. 



Nowhere in the Maldives have we met with better examples of the modi- 

 fying effect of the regular southwest and northeast monsoons as compared to 

 the effect of winds in regions of southerly variable winds and squalls than in 

 the northernmost groups of the Maldives. One can readily trace the direct 

 action of the monsoons upon similar islands when situated either on the east 

 or west face or on the inner waters of the group. Of course all that part of 

 the Tiladummati and Miladummadulu groups which lies north of North 

 Malosmadulu cannot fail to be greatly affected by the action of the south- 

 west monsoon on the western face of the group. 1 Entering Tiladummati to 

 the south of Muradu, we had to stem a current sweeping west with great 

 violence, it being the season of the northeast monsoon. 



It is interesting to note the changes which have taken place in the 

 outlines of many of the islands on the rim reef flats of both the western and 

 eastern faros of the group since 1836. Some of the islands which were 

 isolated at that time and are represented on the charts as single distant 

 islands on opposite extremities of the rim of a faro have either both greatly 



1 Gardiner, loc. cit , p. 315, has called attention to the small importance of the agency even of 

 heavy gales on the edges of the reefs. 



