THE PACIFIC OCEAN. 271 
bare spot on the windward edge at the lowest ebb of 
spring tide. 
Captain Basil Hall has recorded some pleasing 
observations on this singular formation, in his voyage 
to Loo-Choo. He says— 
“The examination of a coral reef during ae dif: 
ferent stages of one tide, is particularly interesting. 
‘When the sea has left it for some time, it becomes 
dry, and appears to be a compact rock, exceedingly 
hard and rugged; but no sooner does the tide rise 
again, and the waves begin to wash over it, than 
millions of coral worms protrude themselves from 
holes on the surface, which were before quite in- 
visible. These animals are of a great variety of 
shapes and sizes, and in such prodigious numbers 
that in a short time the whole surface of the rock 
appears to be alive and in motion. The-most com- 
mon of the worms at Loo-Choo was in the form of a 
star, with arms from four'to six inches long, which 
it moved about with a rapid motion in all directions, 
probably in search of food. Others were so sluggish 
that they were often mistaken for pieces of the rock ; 
these were generally of a dark colour, and from four 
to five inches long, and two or three round. When 
the rock was broken from a spot near the level of 
high-water, it was found to be a hard, solid stone; 
but if any part of it were detached at a level to 
which the tide reached every day, it was discovered 
to be full of worms, all of different lengths and 
colours, some being as fine as a thread, and several 
feet long, generally of a very bright yellow, and 
sometimes of a blue colour; while others resembled 
