FOOD-MATTERS IN THE SEA 327 



Thus we catch glimpses — it is not yet a finished picture — 

 of the endless changes of the ocean ; of both earth and air 

 contributing necessary materials to the water so that those 

 of minimal amount never become exhausted ; of the fishes 

 we eat feeding upon smaller animals, the cod on the hermit 

 and other crabs, the plaice on cockles and mussels, the 

 herring on the larger Copepods of the plankton, and these 

 in their turn on microscopic organisms ; of the carbon 

 dioxide and the silica becoming stored up in winter to be 

 used by the phyto -plankton which has been called into 

 activity by the increasing radiant energy of the sunlight 

 in spring, just in time to nourish the newly hatched post- 

 larval fishes ; of the zoo-plankton that follows, feeding on 

 the phyto -plankton and itself falling prey to the migratory 

 fishes in summer, and the dead remains of everjrthing f aUing 

 to the bottom to form the demerson upon which hordes 

 of benthonic animals can browse. And we recognize that 

 all are links in a series of interlacing chains where nothing 

 is lost, nothing wasted, substances disappearing only to 

 reappear in another form : the carbon and calcium now free 

 in the water as dissociated ions, now locked up in the shell 

 of a mollusc, buried in Globigerina ooze or fossilized as a 

 coral reef ; the silica once in a flint, now in a Radiolarian 

 shell, a Sponge spicule, or a Diatom frustule, to be redissolved 

 in the water when required by the inexorable laws of nature 

 to pass to another phase of the beneficent, never-ending 

 cycle of events that constitutes the metabolism of the 

 oceans. 



The appeal which such researches in pure science make 

 to university laboratories, and to all who desire to advance 

 knowledge, ought to be irresistible ; but there is also a 

 wider appeal, on economic grounds, not to the scientific 

 world alone, but to the whole population of these islands, 

 a maritime people who owe everything to the sea. I urge 

 them to become better informed in regard to our national 

 sea-fisheries and take a more enlightened interest in the 



