598 
ON CORAL REEFS AS A CAUSE OF THE FEVER 
a termination is put to the labours of all. The products of these 
labours are the coral reefs that line or fringe our shores, or form 
the Attoll islands which seem as resting places in a dreary waste 
of water. In ages gone by, their polyps have been at work 
toiling through the lapse of time, and leaving us the vestiges 
of their work in the mountain masses of limestone that are 
to be seen in all parts of the world. The fossiliferous strata, a 
portion of which is the product of coralline polyps, have been esti¬ 
mated to have a thickness of nearly 7 miles, so that the time oc¬ 
cupied in their formation must have been immense. Mrs. Somerville 
says, “ every river carries down mud, sand, or gravel to the sea, the 
Ganges brings down more than 700,000 cubic feet of mud every 
hour, the Yellow river in China 2,000,000, and the Mississippi 
still more, yet notwithstanding these great deposits, the Italian Hy- 
drographer Manfredi has estimated that if the sediment of all the ri¬ 
vers of the globe, were spread equally over the bottom of the ocean, 
it would require a thousand years to raise its bed one foot so that 
at that rate it would require 3,960,000 years to raise the bed of the 
ocean above to the height of the fossiliferous strata.” If it would take 
1000 years for the sediment of all the rivers of the globe to raise 
the bed of the ocean one foot, what time, what labour, and what an 
immensity of labourers must have been required to have raised the 
barrier reefs to the east of Australia, which extend towards the In¬ 
dian Archipelago 1000 miles, having an average breadth of £ of a 
mile and a depth of 200 feet, and this labour executed in spite of ene¬ 
mies as the Helotharia &c., and in defiance of storms, nay even court¬ 
ing the situations, where the waves are highest and the water most 
troubled. My admiration is lost in amazement, and I would exclaim 
if the Heavens shew the handiwork of the Lord, surely the Sea 
does shew his wonders. The majority of the species of coral, when 
they have reached within a short distance of the surface, cease their 
labours, and extend laterally, although there are in the Celebes, Ja¬ 
va, and other places, masses of coral some feet higher than the level 
of the sea, yet that uprising has been the result of volcanic action. 
These corals that are found in deep water are not found living in 
shallow water, some species are found inhabiting the banks of reefs 
in one place at a depth of 3 feet, at another of 3 fathoms, and last¬ 
ly some are found in reefs which are for some hours uncovered by 
the tide, and yet live, among which 1 have found the Madripora frin- 
gia and Meandrina cerebriformis. But the majority of these polyps 
