AGASSIZ: BEKMUDAS. 277 



At the Bermudas we find nothing corresponding to the ocean holes of 

 the Bahamas, unless it be that such cavernous sinks and indentations as 

 occur all along the shores, and which can be detected on the edges of the 

 reefs and ledges, or in the circular areas where the depth is sometimes 

 greater by two to three fathoms than over the adjoining area, may cor- 

 respond to ocean holes, but only on a smaller scale of depth. 



Heilprin thinks " that the height of land in the archipelago was formed 

 during a period of elevation." It seems to me more natural to suppose 

 that the Bermudas were formed during a period of rest, when the level 

 of the reef was stationary, and they were flanked by a broad sand beach 

 with flats perhaps bare at low water. These would supply an abun- 

 dant material for the formation of such dunes as we now find, and may 

 imagine to have existed on the northern edge of the Bermudas and ou 

 the flats which determine the shape of the proto-Bermudian lagoons. 



While I fully agree to the all-important part which subsidence has 

 played in shaping the Bermudas as they now exist, I cannot trace any 

 connection between these facts and the proposition that " the existence 

 of an atoll in the present position of the Bermudas is not demonstrable." 

 We certainly have a group of peolian hills formed from an annular 

 ring of coral reefs which flourished when the land was at least seventy 

 feet higher than at present. But the facts we observe on the islands 

 to-day do not shed one ray of light on the question of the Darwinian 

 theory of the formation of atolls. The position of the reef to which the 

 Bermudas owe their origin can only be surmised, — and probably very 

 correctly, — but we cannot state that it was formed during a period of 

 subsidence, and have no data regarding this point. Subsidence has 

 given to these islands their present configuration. Bat it is begging 

 the question to state that the formation of the proto-Bermudian coral 

 reef, about which Heilprin himself is careful to say we know nothing, if 

 it does "not prove the correctness of the Darwinian theory of the forma- 

 tion of coral islandg, measurably sustains it." ^ 



We may also agree with him in the conclusion that the present form 

 of the Bermuda Islands bears no relation to the ring of an atoll, ^ that 



1 " The question as to what form of coral structure the Bermudas actually are 

 — what constitutes their fundament, and how they were built to their existing 

 level — still remains unanswered, and possibly we may never be able to answer." — 

 Bernmdas, p. 47. 



" Heilprin says: "In the case of the Bermuda Islands, which limit the field of 

 my own investigations in this direction, I am confident that, whatever may have 

 been the original construction of the region, the present lagoon features have been 

 brought about through subsidence ; and tliis conclusion was reached before me by 



