32 Charles Darwin. 



appearance of the water through which the Beagle 

 was sailing. From a rich opalescent-blue, it had 

 changed to a reddish-brown, so that the entire ocean 

 seemed to reflect a copper-bronze hue, weird and 

 uncanny in its aspect. Some of the water, upon 

 being placed under the microscope, appeared to 

 contain large masses of chopped hay, which proved 

 to be conferva of a reddish tint. Some of the 

 patches covered several miles in extent, entirely 

 changing the tint of the ocean. Darwin comments 

 on the fact as remarkable, that these minute forms 

 could keep together in the lines and bands that 

 extended so many miles over the sea. 



The colour of the ocean, from this and similar 

 causes, seems to have engaged his interest at various 

 times. On the coast of Chili he noticed that the 

 water was a dull-red hue, that might have come 

 from some muddy river. This was due, he found, 

 to some minute animal which was, to use his term, 

 continually exploding or throwing out a mass of 

 dark-brown granular matter, probably eggs. He 

 noticed, in one instance, a patch of these animals 

 that covered several square miles, and comments 

 upon the vast numbers of individuals which must 

 have made up the concourse. Later, at Tierra del 

 Fuego, he found the ocean coloured a deep red 

 by the presence of innumerable crustaceans, while 

 near Galapagos the ship forged through water of a 

 rich yellow, due to another source. These are among 

 the causes which give the names yellow, white, and 

 red to the various seas. 



The objective point of the Beagle, after leaving 



