PREFACE 



"VyO one can be better aware of the defects in this 

 J^\ little book than the author. It has been 

 . written with a view to giving a summary of the most 

 important facts about pearls, pearl fishing and pearl 

 formation, and it is hoped by the writer that any sins 

 of omission will be pardoned. There is no lack of 

 literature on the subject of pearls, and some of the 

 volumes which have been published on this subject 

 are themselves of great value. They do not seem, 

 however, to be easily within reach of the average 

 reader, and they are nearly always written from 

 non-biological points of view. The works on pearl 

 formation are, on the other hand, usually very 

 technical. The structure and natural history of the 

 shell-fish in which pearls are produced are hardly 

 ever described outside scientific treatises ; hence 

 the chapter on this subject. It seemed impossible, 

 to the author, to describe the processes of pearl 

 formation without reference to the structure of the 

 shell-fish. If it were only for common knowledge, a 

 description of the anatomy of a mollusc should be 

 interesting to the general reader, for very little idea 

 of the structure of even an edible oyster or mussel 

 seems to prevail. The book has been written by 

 a biologist, from the point of view of a biologist, 



