If your stock be very great, you may let your ponds stand full two or three years, but not longer, unless you delight to see starved lean fish; for such they will certainly be, unless you keep an under-stock by three-fourths continuing in the same water four or five years. And it is a certain rule, that the oftener waters are laid dry, the better the feed of the fish shall be, and more shall be maintained. And a little experience will demonstrate the advantage to be great, as to the size, fatness, and sweetness of the fish. When your pond is dry, concern not yourself to carry out the mud for the first fourteen or fifteen years; and then let it be only out of the pan whence you took the earth to raise the bank, but never break the turf of the rest of the ground flowed: but when it comes to be a yard thick in mere mud, it is good to take it out; for though mud be good to improve ground, yet, when it is taken from the pond, down to the dead earth, your ground and soil are depauperated, and the water by consequence, which cheats the fish, that is, yourself. _Of the Breeding of Fish._ Having done with ponds, the manner of making, preserving, and using them, I intend next to discourse of fish, and how best to dispose them to maintain the waters in full stock: but before I come to the stocking of waters, I must speak of the course of breeding fish, whereby the stock is to be recruited and supplied. Some have thought, that great difference is to be found in the sorts of carps, some whereof are more apt to grow up to a great size, others to spread and look thick, and others for the sweetness of the meat. I do not deny but there may be some difference, but I cannot esteem it so considerable, as to be worth the looking after. Varieties in nature are infinite, and in the several breeds of fish, as of other creatures: yet I have not observed so much of it in carps, that I could tell how to distinguish them, where I could promise myself better success with one sort than another. This is a nicety which fishmongers, that make a trade of buying and selling, talk of, intending it only as a topic of mystery, which all trades affect, and to have something to say for valuing or undervaluing, as they sell or buy, to justify in their talk the prices they propose to take or give; therefore this nicety is left to them.