PREFACE 



TO 



THE THIRD AND FOURTH EDITIONS. 



Nothing can be more agreeable to an author anxious to 

 merit the suffrages of the public, than the opportunity 

 afforded' him, by a new edition, of correcting past errors 

 or adding improvements to his work. Should any one of 

 my readers think it worth his while to compare ' The 

 Sea,' such as it now is, with what it formerly was, I have 

 no doubt he will do me the justice to say that I have 

 conscientiously striven to deserve his approbation. 



Two new chapters — one on Marine Constructions, the 

 other on Marine Caves — have been added ; those on the 

 Molluscs and Ccelenterata (Jelly-fishes, Polyps) almost 

 entirely re-written ; and those on Fishes, Crustaceans, 

 Microscopic Animals, the Geographical Distribution of 

 Marine Life, and the Phosphorescence of the Sea, con- 

 siderably enlarged ; not to mention a number of minor 

 improvements dispersed throughout the volume. 



Great attention has also been paid to the Illustrations, 

 many of questionable value having been omitted in the 

 present edition, to make room for a number of others, 



