SEA-FISHERIES LABORATORY 268 
AN INTENSIVE STUDY OF THE MARINE 
‘PLANKTON AROUND THE SOUTH END OF 
THE ISLE OF MAN.—PART IV. 
By W. A. Herpman, F.R.S., and ANDREW Scott, A.L.S. 
[| ExpLtanatory Notrr.—The work has been carried 
on during 1910 on the same general lines as in the 
previous three yéars. Professor Herdman has_ been 
responsible for collecting the material, partly in Port 
Erin Bay during the year and partly at sea from his 
yacht ‘“* Ladybird’’; while Mr. Scott, at the Piel 
Laboratory, has examined in detail the preserved 
catches, and filled up the forms. This report has been 
drawn up at Liverpool by Professor Herdman, with the 
assistance of Miss H. M. Lewis, who has compiled the 
tables of statistics and plotted the curves. Mr. Wm. 
Riddell again gave most efficient help in the collecting 
operations at sea from the yacht, and both he and 
Mr. H. C. Chadwick took part im straining and preserving 
and measuring the catches at Port Hrin.—W. A. H.| 
INTRODUCTION. 
For full details in regard to our methods we must 
refer to Part I of this series (in the Report for 1907); 
and for the discussion of some points which we consider 
it unnecessary to deal with further, reference must be 
made to one or other of the three preceding parts. In 
fact, although the general arrangement of the matter 
will be the same as in Part III, we shall now give in 
detail only what is new or what we require for 
comparison with the other years, 
