And next you are to note, That till the sun gets to such a height as to warm the earth and the water, the Trout is sick, and lean, and lousy, and unwholesome; for you shall, in winter, find him to have a big head, and, then, to be lank and thin and lean; at which time many of them have sticking on them Sugs, or Trout-lice; which is a kind of a worm, in shape like a clove, or pin with a big head, and sticks close to him, and sucks his moisture, those, I think, the Trout breeds himself: and never thrives till he free himself from them, which is when warm weather comes; and, then, as he grows stronger, he gets from the dead still water into the sharp streams and the gravel, and, there, rubs off these worms or lice; and then, as he grows stronger, so he gets him into swifter and swifter streams, and there lies at the watch for any fly or minnow that comes near to him; and he especially loves the May-fly, which is bred of the cod-worm, or cadis; and these make the Trout bold and lusty, and he is usually fatter and better meat at the end of that month than at any time of the year.
Now you are to know that it is observed, that usually the best Trouts are either red or yellow; though some, as the Fordidge Trout, be white and yet good; but that is not usual: and it is a note observable, that the female Trout hath usually a less head, and a deeper body than the male Trout, and is usually the better meat. And note, that a hog back and a little head, to either Trout, Salmon or any other fish, is a sign that that fish is in season.
But yet you are to note, that as you see some willows or palm-trees bud and blossom sooner than others do, so some Trouts be, in rivers, sooner in season: and as some hollies, or oaks, are longer before they cast their leaves, so are some Trouts, in rivers, longer before they go out of season.
And you are to note, that there are several kinds of Trouts: but these several kinds are not considered but by very few men; for they go under the general name of Trouts; just as pigeons do, in most places; though it is certain, there are tame and wild pigeons; and of the tame, there be hermits and runts, and carriers and cropers, and indeed too many to name. Nay, the Royal Society have found and published lately, that there be thirty and three kinds of spiders; and yet all, for aught I know, go under that one general name of spider. And it is so with many kinds of fish, and of Trouts especially; which differ in their bigness, and shape, and spots, and colour. The great Kentish hens may be an instance, compared to other hens: and, doubtless, there is a kind of small Trout, which will never thrive to be big; that breeds very many more than others do, that be of a larger size: which you may rasher believe, if you consider that the little wren and titmouse will have twenty young ones at a time, when, usually, the noble hawk, or the musical thrassel or blackbird, exceed not four or five.