124 SPOLTA ZEYLANIOA. 



REMARKS ON DR. PEARSON'S REVIEW OF THE 



SCIENTIFIC WORK DONE ON THE CEYLON 



PEARL BANKS FROM 1902 TO 1912. 



By T. Southwell, A.R.C.S. (Lond.), F.Z.S., F.L.S. 



Deputy Director of Fisheries, Bengal, Bihar, and Orissa ; late 



Scientific Adviser and Inspector of Pearl Banks to the 



Ceylon Company of Pearl Fishers. 



THE January issue of Spolia Zeylanica (Vol. VIII., 

 Part XXXII.) contained a review of the scientific work on 

 the Ceylon pearl banks from 1902 to 1912, by Dr. J. Pearson. 

 Certain features of this review call for attention, and will be 

 dealt with as briefly as possible in the following Paper. 



Dr. Pearson states that he was prompted to write his review 

 because of certain misunderstandings which undoubtedly 

 exist, and with a view to determining how far the scientific 

 investigations have progressed towards the attainment of 

 their chief object. Unfortmiately, certain features of the 

 work appear not to have been fully comprehended by the 

 writer of the review, and consequently the review in question, 

 which is in reality a critique, unnecessarily compHcates the 

 whole question. The reveiw is of value, however, as setting 

 forth the opinions of a scientist of considerable standing. It 

 would have been of still greater value had the winter's opinions 

 been formed after, instead of before, some practical experience 

 on the banks had been acquired. We make no special 

 emphasis on this point, however, but as bearing on the question 

 it is interesting to note that with reference to the establish- 

 ment of a close season for the window-pane oyster. Dr. Pearson 

 first stated {Spolia Zeylanica, Vol. VII., Part XXIX.) that 

 he agreed with Hornell that a close season for that oyster 

 should be estabHshed from Maj^ to January, but after some 

 practical experience on the banks in question, which have 

 rendered it likely that these oysters spawn during January 

 and February, Dr. Pearson is now of opinion that fishing on 

 the Placuna beds should be restricted to the months of March, 



