PROF. HERDMAN'S practical demonstration at the North Cape confirms a theory I have long held, that the Copepoda, which abound in every ocean, sea, and lake, might be largely and advantageously made available for human food. It is well known that the species Calanus finmarchicus, so abundant in our northern seas, forms the chief food of the Greenland whale. Our own immediate coasts abound in this and other equally edible species. During a recent dredging cruise round the Isle of Man, each pull of the tow-net contained thousands of another and larger species of Copepod, Anomalocera patersonii; and Dr. John Murray has found that a still larger species, Euchaeta norvegica, is plentiful in the lower depths of several Scotch lochs.