X] PEARLS AND SCIENCE 131 



whether it might not be possible to prevent the 

 recurrence of such periods. Professor W. A. Herd- 

 man, F.R.S., was selected^ on the advice of the 

 Council of the Royal Society and of Sir Ray 

 Lankester, then director of the British Museum, 

 for the purpose of conducting a thorough investiga- 

 tion of the pearl banks. He took with him as an 

 assistant, ]\fr James Hornell, and left England at 

 the end of 1901 for a visit to the Gulf of ^Nlanaar. 



During the three months of Herdman's sojourn 

 at the island, cruises were made on a steamer fitted 

 for the investigation and all the principal pearl banks 

 were examined. Dredging, trawling and diving were 

 carried out, and the biologists also took part in the 

 annual government inspection of the pearl banks. 



As a result of this expedition the condition of 

 the pearl banks was made known in great detail. 

 Collections were made of the animals and plants 

 living along with the pearl oysters. Some of these 

 are merely passive neighbours, others are active 

 enemies or competitors for food. It was necessary 

 to determine what factors influenced the pearl oysters 

 in their growth in order, if possible, to arrive at the 

 causes of failure of fisheries. Herdman s reports con- 

 tain a mine of information, and we must say that the 

 work which the expedition was sent to accomplish, 

 was carried out thoroughly and successfully. 



After Herdman returned to England, Hornell 



9—2 



