186 CORALLINE BOCKS 



Three days elapsed before we could emerge from this 

 labyrinth of Jardines and Jardinillos. At night we lay at 

 anchor ; and in the day we visited those islands or chains 

 of rocks which were most easily accessible. As we advanced 

 eastward, the sea became less calm, and the position of the 

 shoals was marked by water of a milky colour. On the 

 boundary of a sort of gulf between Cayo Flamenco and 

 Cayo de Piedras, we found that the temperature of the 

 sea, at its surface, augmented suddenly from 23*5 cent, 

 to 25*8. The geologic constitution of the rocky islets that 

 rise around the island of Pinos, fixed my attention the more 

 earnestly, as I had always rather doubted of the existence of 

 those huge masses of coral which are said to rise from the 

 abyss of the Pacific to the surface of the water. It ap- 

 peared to me more probable that these enormous masses 

 had some primitive or volcanic rock for a basis, to which 

 they adhered at small depths. The formation, partly com- 

 pact and lithographic, partly bulbous, of the limestone of 

 Guines, had followed us as far as Batabano. It is some- 

 what analogous to Jura limestone ; and, judging from their 

 external aspect, the Cayman Islands are composed of the 

 same rock. If the mountains of the island of Pinos, which 

 present at the same time (as it is said by the first historians 

 of the conquest) the pineta and palmeta, be visible at the 

 distance of twenty sea leagues, they must attain a height of 

 more than five hundred toises: I have been assured that 

 they also are formed of a limestone altogether similar to that 

 of Guines. From these facts, I expected to find the same 

 rock (Jura limestone) in the Jardinillos : but I saw, in the 

 chain of rocks that rises generally five to six inches above 

 the surface of the water, only a fragmentary rock, in which 

 angular pieces of madrepores are cemented by quartzose 

 sand. Sometimes the fragments form a mass of from one 

 to two cubic feet, and the grains of quartz so disappear, 

 that in several layers one might imagine that the polypi 

 have remained on the spot. The total mass of this chain 

 of rocks appears to me a limestone agglomerate, somewhat 

 analogous to the earthy limestone of the peninsula of Araya, 

 near Cumana, but of much more recent formation. The 

 inequalities of this coral rock are covered by a detritus of 

 hells and madrepores. Whatever rises above the surface 



