Page:The Zoologist, 4th series, vol 3 (1899).djvu/373

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MIMICRY.
345

description, are constantly feeding on them from the moment of their birth. The shoals of Herring in the ocean are always accompanied by flocks of Gulls and other sea-birds, which are continuously preying upon them, and it seems therefore no exaggeration to conclude that man does not destroy one Herring for every fifty destroyed by other enemies. The destructive power of man therefore is insignificant when it is compared with the destructive agencies which nature has created; and nothing that man has done, or is likely to do, has produced, or will probably produce, any appreciable effect on the number of Herring in the open sea.[1] In 1781 the town of Gottenburg alone exported 136,649 barrels, each containing 1200 Herrings, making a total of about 164,000,000; but so rapid was the exhaustion of the fish from this keen pursuit, that in 1799 it was found necessary to prohibit the exportation of them altogether.[2] This is a conclusion somewhat opposed to the opinion of Frank Buckland, as related above; but our aim here is only to show what multifarious dangers the Herring survives.[3]

The Salmon deposits nearly a thousand eggs for every pound of its live weight. But nature is prolific in her waste, and a whole army of her poachers have to be satisfied. "So true is this, that the yearly yield of the largest Salmon-producing river in the kingdom is computed at about the produce of one female fish of from fifteen pounds to twenty pounds in weight."[4] Mr. J.W. Willis Bund, the Chairman of the Severn Fishery Board, estimates that of Salmon eggs only 10 per cent., or 100,000 per million, hatch out. "Nothing Trout like better than Salmon ova; Eels regard it as a delicacy; while Water-hens, Water-Ouzels, Crows, and other birds, as soon as any part of the bed of the stream is either uncovered, or has only a few inches of water in it, go over it again and again, picking out the tit-bits the ova are to them."[5] As to the mortality at the subsequent stages, estimating the number of ova hatched as 1,000,000 out of

  1. 'Life of Frank Buckland,' by G.C. Bompas, 2nd edit. pp. 313–14.
  2. 'Das Leben des Meeres,' p. 182.—Cf. Marsh, 'Man and Nature,' p. 120, note.
  3. The excessive spermatozoa of the Herring sometimes whitens the water for scores of square miles (Matthias Dunn, 'Contemp. Rev.' lxxvi. p, 200).
  4. Thomas Watson, 'Poachers and Poaching,' p. 165.
  5. 'The Life of a Severn Salmon,' p. 7.