FullReads

Whether trout have not a specific fondness for lime; whether water of some dozen degrees of hardness is not necessary for their development? are questions which may be fairly asked. Yet is not the true reason this; that the soil on the banks of a chalk or limestone stream is almost always rich–red loam, carrying an abundant vegetation, and therefore an abundant crop of animal life, both in and out of the water? The countless insects which haunt a rich hay meadow, all know who have eyes to see; and if they will look into the stream they will find that the water-world is even richer than the air-world.

Every still spot in a chalk stream becomes so choked with weed as to require moving at least thrice a year, to supply the mills with water. Grass, milfoil, water crowfoot, hornwort, starwort, horsetail, and a dozen other delicate plants, form one tangled forest, denser than those of the Amazon, and more densely peopled likewise.

To this list will soon be added our Transatlantic curse, Babingtonia diabolica, alias Anacharis alsin astrum. It has already ascended the Thames as high as Reading; and a few years more, owing to the present aqua-vivarium mania, will see it filling every mill-head in England, to the torment of all millers. Young ladies are assured that the only plant for their vivariums is a sprig of anacharis, for which they pay sixpence–the market value being that of a wasp, flea, or other scourge of the human race; and when the vivarium fails, its contents, Anacharis and all, are tost into the nearest ditch; for which the said young lady ought to be fined five pounds; and would be, if Governments governed. What an ‘if’.

But come; for the sun burns bright, and fishing is impossible: lie down upon the bank, above this stop. There is a campshutting (a boarding in English) on which you can put your elbows. Lie down on your face, and look down through two or three feet of water clear as air into the water forest where the great trout feed.

Here; look into this opening in the milfoil and crowfoot bed. Do you see a grey film around that sprig? Examine it through the pocket lens. It is a forest of glass bells, on branching stalks. They are Vorticellae; and every one of those bells, by the ciliary current on its rim, is scavenging the water–till a tadpole comes by and scavenges it. How many millions of living creatures are there on that one sprig? Look here!–a brown polype, with long waving arms–a gigantic monster, actually a full half-inch long. He is Hydra fusca, most famous, and earliest described (I think by Trembley). Ere we go home I may show you perhaps Hydra viridis, with long pea-green arms; and rosea, most beautiful in form and colour of all the strange family. You see that lump, just where his stalk joins his bell-head? That is a budding baby. Ignorant of the joys and cares of wedlock, he increases by gemmation. See! here is another, with a full-sized young one growing on his back. You may tear it off if you will–he cares not. You may cut him into a dozen pieces, they say, and each one will grow, as a potato does. I suppose, however, that he also sends out of his mouth little free ova–medusoids–call them what you will, swimming by ciliae, which afterwards, unless the water beetles stop them on the way, will settle down as stalked polypes, and in their turn practise some mystery of Owenian parthenogenesis, or Steenstruppian alternation of generations, in which all traditional distinctions of plant and animal, male and female, are laughed to scorn by the magnificent fecundity of the Divine imaginations.

That dusty cloud which shakes off in the water as you move the weed, under the microscope would be one mass of exquisite forms–Desmidiae and Diatomaceae, and what not? Instead of running over long names, take home a little in a bottle, put it under your microscope, and if you think good verify the species from Hassall, Ehrenberg, or other wise book; but without doing that, one glance through the lens will show you why the chalk trout grow fat.