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TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY 



The tow-net (figs. E and F) is a conical bag of 

 muslin or silk, which can be towed through the water 

 behind a boat, so as to strain out all the microscopic 

 organisms. Fig. F shows a mo-re complicated form for 

 very exact work, and fig. E a simpler tow-net, with, 

 however, an electric lamp fixed in the interior in order to 

 attract swimming animals in the dark. Many very rare 

 animals have been captured in this way by an electric- 

 light-net lowered at night to the bottom of the sea. 



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 Pig. Q . — Arrangement for collecting Plankton on a " Liner. 



When on board a steamer going so fast that it would 

 be impossible to tow a net through the water, it is still 

 possible to get a good gathering of plankton by tying the 

 tow-net over some tap on board which communicates with 

 a tank into which the sea is being pumped. Fig. G 

 shows such an arrangement on the deck, but quite as 

 good a plan is to use one of the bathrooms and run the 

 sea-water tap day and night through nets which are 

 periodically changed. In this way it is possible, on any 



