SEA-FISHERIES LABORATORY. 369 



AN INTENSIVE STUDY OF THE MARINE 

 PLANKTON AROUND THE SOUTH END 01 

 THE ISLE OF MAN.— PART VII. 



By W. A. Herdman, F.R.S., Andrew Scott, A.L.S., 

 and H. Mabel Lewis, B.A. 



This Part gives a brief account of the results obtained 

 during 1913 — the seventh year of our detailed analysis of 

 the plankton collected week by week at Port Erin. Our 

 intention is to complete, if possible, ten years of continuous 

 observations before bringing this scheme of work to a 

 conclusion. At the time when this is being written, the 

 eighth year's work has been well inaugurated by the taking 

 during the period of the vernal phyto-plankton of over 

 a hundred special hauls, in addition to the usual weekly 

 gatherings in Port Erin Bay. 



The division of labour has been practically the same 

 as in the case of previous reports. The work at sea during 

 April, 1913, was carried on, as before, from the yacht 

 "Runa," with the very efficient help of Mr. H. G. 

 Jackson, M.Sc. ; while in Port Erin Bay Mr. Chadwick and 

 Mr. Cregeen, of the Biological Station, collected and 

 preserved about six samples a week throughout the year — 

 two with a fine net (No. 20 silk), two with a coarser 

 (No. 9 silk), and two vertical hauls, from 5 fathoms, at the 

 mouth of the bay. 



The authors have divided between them the rest of the 

 work — the examination and calculation and writing out 

 of the results — on the same plan as in previous years. 



We do not regard the present report as an exhaustive 

 statement of the results to be obtained from B study of 

 the material collected. These are only of the nature of 

 interim reports. All our samples are carefully retained, 



