MAEINE BIOLOGICAL STATION AT PORT ERIN. 43 



and waves, and are not carried entirely by tidal streams. 

 "Well, that is an advantage rather than any objection to 

 the method. For our object is to determine not the tidal 

 currents alone but the resulting effect upon small surface 

 organisms such as floating fish eggs, embryos and fish food, 

 of all the factors which can influence their movements, 

 including prevalent winds. The only factors which can 

 vitiate our conclusions are unusual gales or any other quite 

 exceptional occurrences, and the only way to eliminate 

 such influences is (1) to allow for them so far as they are 

 known from the weather reports, and (2) to employ a 

 large number of drift bottles and continue the observations 

 over a considerable time. We have carefully considered 

 the bearing of the weather records, and we think that 

 the large number of bottles we have made use of, during 

 the year, ought to enable us to come to some definite 

 results. Our conclusions so far (November) then are : — 



(1) A large number (over 34 %) have been stranded and 

 found and returned, (2) only a small proportion (13 %) 

 have been carried out of our part of the Irish Sea, (3) 

 nearly 12 % have crossed the " head of the tide " showing 

 the influence of wind in carrying floating bodies over from 

 one tidal system into another, (4) most of the bottles set 

 free to the west of the Isle of Man have been carried 

 across to Ireland, only a small number (3*8 %) of them 

 have got round to the eastern side of the Island and 

 been carried ashore on the English coasts, (5) the majority 

 of the bottles set free off Dalby have gone to the Co. 

 Down coast, (6) a considerable number of bottles have 

 been set free over the deep water to the east of the Isle 

 of Man, where our more valuable flat fish spawn, and of 

 those that have been returned the majority had been 

 carried to the Lancashire, Cheshire and Cumberland 

 coasts. So we may reasonably conclude that the embryos 



