from Izaak Walton's The Compleat Angler

The Salmon is ever bred in the fresh Rivers (and in most Rivers about the month of August) and never grows big but in the Sea; and there to an incredible bigness in a very short time; to which place they covet to swim, by the instinct of nature, about a set time: but if they be stopp'd by Mills, Floud-gates or Weirs, or be by accident lost in the fresh water, when the others go (which is usually by flocks or sholes) then they thrive not.

And the old Salmon, both the Melter and Spawner, strive also to get into the Sea before Winter; but being stopt that course, or lost, grow sick in fresh waters, and by degrees unseasonable, and kipper, that is, to have a bony gristle, to grow (not unlike a Hauks beak) on one of this chaps, which hinders him from feeding, and then he pines and dies.

 

This text is linked to:
Lecture 13