Read it through once

First: The uncertain, unsettled condition of this science of Cetology is in the very vestibule attested by the fact, that in some quarters it still remains a moot point whether a whale be a fish. In his System of Nature, A. D. 1776, Linnæus declares, “I hereby separate the whales from the fish.” But of my own knowledge, I know that down to the year 1850, sharks and shad, alewives and herring, against Linnæus’s express edict, were still found dividing the possession of the same seas with the Leviathan.