PREFACE. 



THIS Report on the Pearl Fisheries and Marine Biology of Ceylon has required a 

 much greater expenditure of time and labour, and has extended to a greater length, 

 than was contemplated at the outset. In the winter of 1901, it was supposed that 

 about one year must elapse, after my return from Ceylon, before the Report could be 

 completed, but the necessary work has occupied all my leisure for over four years, and 

 I am painfully conscious that it is still unfinished there are several matters I should 

 like to have included, or to have followed up further, had time for investigation and 

 funds for publication been less limited. 



But this must be the final volume, and I wish now, in bringing the work to an end, 

 to make use of this opportunity mainly for the purpose (l) of reiterating my thanks 

 to many friends who have kindly helped me, (2) of correcting such errors and 

 omissions* in the former volumes as have come to my notice, and (3) of saying my final 

 word as to the present position and future prospects of the pearl fisheries. 



I have reluctantly come to the conclusion that an index to the five volumes is 

 impracticable. If it contained all specific names it would be largely an unjustifiable 

 repetition of our lists, and every Zoologist who consults the work will be readily able 

 to find any desired species from the classifications given in the reports. It may, 

 however, be some aid to the reader if I give here a scheme indicating in which Part 

 each section of the subject and each special report will be found. The sections of the 

 pearl-oyster report proper are arranged in chronological order, as that corresponds 

 with the natural development of the subject, from preliminaries to final conclusions, 

 and the special, or "supplementary," reports are placed in zoological order from the 

 lowest groups to the highest, so that the position of each in the volumes can be 

 ascertained from this list at a glance. 



PEARL OYSTER REPORT. 



INTRODUCTION Part L, p. 1. 



NARRATIVE AND OUTLINE OF THE INVESTIGATIONS . . . . ,, L, p. 17. 



DESCRIPTION OF THE PEARL BANKS ,, I., p. 99. 



OBSERVATIONS ON THE SEA ,, L, p. 122. 



OBSERVATIONS AND EXPERIMENTS ON THE PEARL OYSTER . . ,, I., p. 125. 



HISTORY OF THE PRINCIPAL PEARL BANKS ,, II., p. 1. 



ANATOMY OF THE PEARL OYSTER ,, II., p. 37. 



PARASITES OF THE PEARL OYSTER ,, II., p. 77. 



* See p. 449. 



