And now for some confirmation of this; you are to know, that this Trout is thought to eat nothing in the fresh water; and it may be the better believed, because it is well known, that Swallowes, which are not seen to flye in England for six months in the year, but about Michaelmas leave us for a hotter climate; yet some of them, that have been left behind their fellows, [view Sir Fra. Bacon exper. 899.], have been found (many thousand at a time) in hollow trees, where they have been observed to live and sleep [see Topsel of Frogs] out the whole winter without meat; and so Albertus observes that there is one kind of Frog that hath her mouth naturally shut up about the end of August, and that she lives so all the Winter, and though it be strange to some, yet it is known to too many amongst us to bee doubted.
And so much for these Fordig Trouts, which never afford an Angler sport, but either live their time of being in the fresh water by their meat formerly gotten in the Sea, (not unlike the Swallow or Frog) or by the vertue of the fresh water only, as the Camelion is said to live by the air.
There is also in Northumberland, a Trout, called a Bull Trout, of a much greater length and bignesse then any in these Southern parts; and there is in many Rivers that relate to the Sea, Salmon Trouts as much different one from another, both in shape and in their spots, as we see Sheep differ one from another in their shape and bigness, and in the finess of their wool: and certainly as some Pastures do breed larger Sheep, so do some Rivers, by reason of the ground over which they run, breed larger Trouts.
Now the next thing that I will commend to your consideration is, That the Trout is of a more sudden growth then other fish: concerning which you are also to take notice, that he lives not so long as the Pearch and divers other fishes do, as Sir Francis Bacon hath observed in his History of life and death.
And next, you are to take notice, that after hee is come to his full growth, he declines in his bodie, but keeps his bigness or thrives in his head till his death. And you are to know that he wil about (especially before) the time of his Spawning, get almost miraculously through Weires and Floud-Gates against the stream, even through such high and swift places as is almost incredible. Next, that the Trout usually Spawns about October or November, but in some Rivers a little sooner or later; which is the more observable, because most other fish Spawne in the Spring or Summer, when the Sun hath warmed both the earth and water, and made it fit for generation.
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 lowsie, and unwholsome: for you shall in winter find him to have a big head, and then to be lank, and thin, & 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 a Pin, with a big head, and sticks close to him and sucks his moisture; those I think the Trout breeds himselfe, and never thrives til he free himself from them, which is till warm weather comes, and then as he growes stronger, he gets from the dead, still water, into the sharp streames 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 flie or Minow that comes neer to him; and he especially loves the May flie, which is bred of the Cod-worm or Caddis; and these make the Trout bold and lustie, and he is usually fatter, and better meat at the end of that month, then 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 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 then the male Trout; and a little head to any fish, either Trout, Salmon, or 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 blossome sooner then others do, so some Trouts be in some Rivers sooner in season; and as the Holly or Oak are longer before they cast their Leaves, so are some Trouts in some Rivers longer before they go out of season.