20 PEOCEEDINGS OF THE 



The last address which I deHvered to you from this Chair dealt 

 with the principles underlying the organisation of Fishery 

 Research in this country, and with the methods of investigation of 

 that floating life of the ocean which is of enormous importance in 

 connection with the food supply from the sea. 



The method has been adopted by Naturalists and Oceano- 

 graphers of taking samples of this floating life or plankton with 

 fine silk nets of known straining capacity, the hypothesis being 

 that if we know the contents of a small sample of water we can 

 calculate the living contents of the ocean. It is obvious that this 

 hypothesis rests upon the assumption that the organisms in 

 questions are distributed with such uniformity that small samples 

 of the water are representative of the whole. I have devoted all 

 my spare time for the last couple of years to work at sea with 

 various kinds of closing and open tow-nets designed for the 

 purpose of testing this assumption. What I laid before you last 

 year was of the nature of a preliminary announcement giving the 

 first impressions received from observation of the catches. Since 

 then, however, the six or seven hundred gatherings which I took 

 from the yacht ' Ladybird ' in the seas around the Isle of Man 

 during the year 1907 have all been exhaustively examined by our 

 Associate, Mr. Andrew Scott ; and from his lists and my own 

 observations I have drawn some arguments and] conclusions *, 

 with a few of which I propose to trouble you. 



First, as to the data : — We have nearly 900 gatherings taken in 

 the year 1907 in the northern portion of the Irish Sea, and of 

 these about 650 are from a limited area in the immediate neigh- 

 bourhood of Port Erin. At the south end of the Isle of Man, 

 where these gatherings were taken, there are very important 

 fishing grounds M'hich are frequented by trawlers from Lancashire 

 and from Ireland, as well as by the Manx fishermen. This, as 

 well as the circumstance that we have there, within a few 

 miles, a sheltered sandy bay, an exposed rocky coast, a narrow 

 strait through which strong tides run and an area of open sea with 

 depths reaching to 70-80 fathoms, has led me to consider Port 

 Erin a very suitable locality for a thoroughly exhaustive or 

 intensive study of the Marine Plankton. 



I think it desirable to point out here that the sea off Port Erin 

 cannot be regarded as an exceptional locality. The narrow strait 

 known as the Calf Sound (IV on map opposite) where the tidal 

 currents run with great velocity is, no doubt, exceptional in some 

 respects ; but the open sea, 5 to 10 miles off land (I and II on 

 map), has no physical peculiarities such as would lead us to expect 

 any unusual distribution of organisms. 



It may be useful to repeat here the same little map that I used 

 last year in order to show the localities at which the gatherings 

 were taken. The nets used, it will be remembered, were : — Two 



* A detailed account of the results upon which these conclusions are based 

 will be [and since this was written lias been] published in the Lancashire Sea- 

 Fisheries Laboratory Keport for 1907 (Trans. Liverpool liiol. Soe. vol. xxii.). 



