The Modern Centrifugal Pump as a Plankton Collector

THE elimination of the many sources of error encountered in some form or another when collecting plankton for quantitative work with silk nets is a problem that has been attacked many times. During the last fifty years, a number of workers, many of them with some measure of success, have from time to time used a pump and filter as a means of collecting a small, but quantitatively accurate sample, of plankton.