FLOATING PLANTS 



125 



a few centimetres of water always remain at the point 

 of the cone. Into this wash down the sides of the 

 filter with a pipette, so as to remove any specimens 

 which may have stuck there. This water can then be 



Fig. 43- — Coccosph^ra 

 ("Blake"). 



Fig. 44. — Rhabdosph^era 

 ("Blake"). 



Fig. 45. — Pyrocystis Noctiluca ("Challenger 



poured off, or by perforating the tip of the cone run 

 off into a bottle, for preservation with spirit or other 

 chemical. 



If a paper filter be used it should be of the specially 

 " hardened " paper (Schleicher and Schull's, to be had 

 from dealers in chemical apparatus). 



