HOW PONDS ARE PEOPLED.

Bruce Herald, Volume XXII, Issue 2263, 8 May 1891, Page 6

HOW PONDS ARE PEOPLED.

Supposing a newpond to'be 1 forriaed at some distance from any-previously existI ing .piece .pi.yrater, how .is it that, before long^t^jjoq^eaihickity populated ' and what forms ate likely to' arrive first? Now, the air ,we ,breathe is full o£ small pecks of, dust 1 called motesj ,as 'may ,be seen'wfieri a ray J of sunlight is shining, into a room. Many 1 of these specks or motes are nothing more than the germs or eggs, of tne thousand and, one animalcules so 'prevalent in all waters. JAls soon as ever these germs alight on water, development commences, and the matured individuals, bytheir rapid multiplication, speedily stock the new-found situation with life. The insects, of course, find, their way thither on the wing. The ; beetles, especially Dytious, are great nocturnal fliers, plunging do rim at cockcrow into the nearest piece of water ; hence their occasional presence in waterbutts, or the durance vile of a roadside puddle. The newts and frogs, too, .will travel by the overland route ; but how do the snails get there ? This has been answered by Mr Darwin, who suspended the feet of a duck in an aquarium, where the eggs of fresh-water shells were hatching. Some of the young snails crawled on to these feet, and adhered so firmly that they could not be jarred off, though readily falling at a more advanced age. These young molluscs when taken out of the water survived in damp air from 1 2 to 24 hours, during which period a long journey could be made by the bird. The same observer also mentions that a Dyticus was caught with an Ancylus firmly adhering to it ; and were any one to take the trouble of intercepting thess beetles during their nocturnal excursions, they would doubt less be found to play an important part in thus distributing the smaller species of water-creatures. The transference of fish from place to place, without calling in the aid of the juvenile angler, is, however, a question that does not admit of easy solution at present. The seeds of plants, on the other hand, may be transported in many ways. — From Science for All. ■ ,