70 THE HAUNTS OF LIFE 



animals, such as the small crustaceans called 

 water-fleas, and these may be eaten by fishes. 

 The bodies of dead animals are broken down 

 by microbes, and what is not devoured by other 

 animals passes in solution into the sea-water 

 and may be absorbed again as part of the food 

 of Algae. The same is true of the waste-pro- 

 ducts voided from the food-canal and kidneys 

 of animals. Nothing is ever lost ; all things 

 flow. 



The naturalists at the Plymouth Biological 

 Station have shown that the abundance of 

 mackerel in the spring months depends on the 

 abundance of the minute " water-fleas " or cope- 

 pods in the upper waters, and this again depends 

 upon the abundance of minute Algae called 

 Diatoms and of minute animals called Peridinid 

 Infusorians, which form a great part of the 

 " stock " of the sea-soup. As the multiplication 

 of the Diatoms and Infusorians in the surface 

 waters depends mainly on the amount of sun- 

 light in the early part of the year, we can see a 

 connection between the sunniness of the spring 

 and the supply of mackerel at Billingsgate. 

 The whole world is run on a plan of successive 

 re-incarnations. Diatom or Infusorian, first link ; 

 copepod or water-flea, second link ; mackerel, 



