MAEINE BIOLOGICAL STATION AT POET EEIN. 63 



5000 ova, measuring each about 0*7 mm. in diameter. So 

 that in the Galocaris the ova are about three times as large, 

 but not nearly so numerous, as in the case of its shallow 

 water relation. 



The "Deift Bottles." 



In connection with the investigation of the surface life, 

 in discussing the appearance and disappearance of swarms 

 of certain Copepods and Medusae, and in considering the 

 possible influence ol the movements of food matters upon 

 the migrations of fishes, it has occurred to several of us at 

 different times during the last few years, that it would be 

 worth while to try to ascertain the set of the chief 

 currents, tidal* or otherwise, such as the movement of 

 surface waters caused by prevalent winds. The Prince 

 of Monaco started a few years ago the system of distri- 

 buting over the North Atlantic large numbers of small 

 floating copper vessels, with the object of finding out 

 where they drifted to. This plan we have adopted, with 

 slight modifications. In September I selected a small, 

 strong, buoyant bottle, measuring 7'5 cm. by 1*8 cm., 

 which seemed well suited for the purpose, and which costs 

 only 7s. per gross. I drew up a notice, as follows, to go 

 in the bottles, and had a large number printed and num- 

 bered consecutively : — 



* The tidal currents of the district are already to some extent known, and 

 are marked in the charts and given in books of sailing directions, as Admiral 

 Beechey's "Tidal Streams of the Irish Sea " but we desire to ascertain the 

 resultant currents from all influences which would affect the drift of small 

 floating bodies. 



