300 Hicks on the ^Reef=(Builders. 
ment just as any sandspit is shaped. A counter current to 
the gulf stream sets into the gulf from the Atlantic, carries 
the coral debris along with it, and spreads it out in a long 
curved tongue in the line of the Keys. The coral sand soon 
hardens, and upon the foundation thus furnished the polyps 
take root (at a depth no greater than 42 feet in this region) 
and build uj) to the level of low tide where the waves take 
up and finish the work. 
Such is the statement of Agassiz, who discredits the subsid- 
ence theory of Darwin. But, in order to make good my claim 
that there is no dispute about the essential facts, I quote from 
Prof. James D. Dana, the most illustrious advocate and ex- 
pounder of Darwin's theory. "The facts presented by lieuten- 
ant Hunt, and more fully by Mr. Agassiz, with regard to the 
effects of the eddy current of the gulf stream, show that 
coial reefs may be elongated, and also that inner channels 
may be made, by the drifting of coral sands. But the ac- 
tion with coral sands is essentially the same as with other 
sands; and illustrations of this drifting process occur along the 
whole eastern coast of North America from Florida to Long 
Island. We there learn that drift-made beaches run in long 
lines between broad channels or sounds and the ocean ; that they 
have nearly the uniform direction of the drift of the waters, 
wich some irregularities introduced by the forms of the coast 
and the outflow of the inner waters which are tidal and fluvial 
and have much strength during ebb tide. The easy consolida- 
tion of coral sands puts in a peculiar feature, but not one that 
affects the direction of drift accumulation." ^ 
Dana corroborates Agassiz fully in regard to the facts, but 
later in the same article he draws the inference that there has 
been "a great subsidence "in the reef region of Florida aud the 
West Indies. This inference encounters serious obstacles. 
Several concentric reefs form the southern extremity of the 
peninsula. They are thin reefs; their summits are all about at 
the same level ; they seem to have been formed succesively, not 
simultaneously; and lastly the process and method of their for- 
mation without subsidence seems to have been fairly demon- 
strated by observation on the spot. 
2 Am. Journal of Science, Sept. 1885 p. 178. 
