LIFE IN A POND 



Suppose yourself to be a fish two or three inches long, and 

 accustomed to the dim, mysterious light which filters down 

 through the water from the sky above. Every here and 

 there great olive-brown leaf-stalks and stems cross and, 

 branching, intercept the light. Everything, the surface of the 

 mud, the stems and branches of the submerged water-plants, 

 is covered by an exquisite golden-brown powder, which 

 consists of hundreds and thousands of "Diatoms."" Here 

 and there from the Pondweed and other stems hang festoons 

 or wreaths or threads of beautiful green Algae. Little 

 branching sprays of them, or perhaps of the brown kind, are 

 attached here and there to the thick stems. 



Even the very water is full of small, floating, vivid green 

 stars or crescents or three-cornered pieces which are free 

 floating Algas or Desmids. Other diatoms are also free or 

 swim with a cork-screwing motion through the water. Great 

 snails and slugs crawl upon the plants, and weird large-eyed 

 creatures, with a superfluity of legs and an entire absence 

 of reserve as to what is going on inside their bodies, skirmish 

 around. So that such a pond is full of vegetable activity. 

 The free-swimming diatoms and desmids make up the food 

 of the snails and crustaceans. These latter in turn are the 

 food of fishes. 



It is even possible to-day by carefully stocking an artificial 

 pond with water plants, by then introducing MoUusca and 

 Crustacea, and finally by the introduction of " eyed ova " or 

 fry of the trout, carp, or other fishes, to produce a regular 

 population of fishes which can be made more or less 

 profitable, and the process can be spoken of as "fish- 

 farming.'* Unfortunately there are a great many gaps in 

 our knowledge as to what fish actually feed on, and we know 

 even less about what the Mollusca and Crustacea require. 



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