Perch
2 of the 6 encyclopedias on this shelf carry an entry for Perch. Both are reproduced below, so you can see where they agree and where they differ.
Aiton's Encyclopedia (1910)
a genus of fish belonging to the same family as the "wall-eyed pike." The American perch is from six to twelve inches long with well developed fins, a large mouth, and yellow sides with six to eight dark bands across the back. Perch are found in all clear inland water, and, aside from size, are a fine table fish. They bite freely and are depended upon to fill up a string when larger fish fail. The perch is a very good, and a very bold biting fish. He is one of the fishes of prey that . . . carries his teeth in his mouth, which is very large. . . He has a hooked or hog back . . . and hath, which few other fish have, two fins on his back. He is so bold that he will invade one of his own kind. . . . To affright the pike and save himself, the perch will set up his fins, much like as a turkey-cock will sometimes set up his tail. . . . I will give you but this advice that you give the perch time enough when he bites; for there was scarce ever any angler that has given him too much. And now I think best to rest myself, for I have almost spent my spirits with talking so long.--Walton, The Compleat Angler.
Collier's New Encyclopedia (1921)
Perca fluviatilis, the river perch. The upper part of the body is of a warm, greenish-brown tint, becoming golden on the sides, and white on the belly; there are always broad, vertical, dark bands passing down the sides. The perch is generally distributed America, Europe, and northern Asia, frequenting still over waters, and sometimes descending into brackish waters. Perch feed on smaller fish, insects, and worms. The female deposits her eggs, united by a viscous matter, in long bands, on aquatic plants. The Great Lakes in the United States abound in perch.
What Has Changed in the Last Century
The fish themselves are much as Aiton's described in 1910 and Collier's in 1921 — bold biters, spiny-finned, banded, still filling out a string when bigger fish refuse. The main correction is taxonomic: Collier's listed the perch as Perca fluviatilis "generally distributed America, Europe, and northern Asia," whereas the North American yellow perch is now treated as a separate species, Perca flavescens, with fluviatilis confined to Europe and northern Asia. That European perch has since become a serious invader elsewhere, notably as the "redfin" in Australian rivers, while yellow perch remain a major commercial catch in Lake Erie, now managed under strict annual quotas. Aiton's link to the "wall-eyed pike" holds up: the walleye, Sander vitreus, is indeed a member of the same family, Percidae.
Written for this edition, 2026.