GUIDE TO THE STUDY OF FISHES [Illustration] [Illustration] A GUIDE TO THE STUDY OF FISHES BY DAVID STARR JORDAN _President of Leland Stanford Junior University_ _With Colored Frontispieces and 427 Illustrations_ IN TWO VOLUMES VOL I. "I am the wiser in respect to all knowledge and the better qualified for all fortunes for knowing that there is a minnow in that brook."--_Thoreau_ [Illustration] NEW YORK HENRY HOLT AND COMPANY 1905 Copyright, 1905 BY HENRY HOLT AND COMPANY Published March, 1905 To Theodore Gill, Ichthyologist, Philosopher, Critic, Master in Taxonomy, this volume is dedicated. PREFACE This work treats of the fish from all the varied points of view of the different branches of the study of Ichthyology. In general all traits of the fish are discussed, those which the fish shares with other animals most briefly, those which relate to the evolution of the group and the divergence of its various classes and orders most fully. The extinct forms are restored to their place in the series and discussed along with those still extant. In general, the writer has drawn on his own experience as an ichthyologist, and with this on all the literature of the science. Special obligations are recognized in the text. To Dr. Charles H. Gilbert, he is indebted for a critical reading of most of his proof-sheets; to Dr. Bashford Dean, for criticism of the proof-sheets of the chapters on the lower fishes; to Dr. William Emerson Ritter, for assistance in the chapters on _Protochordata_; to Dr. George Clinton Price, for revision of the chapters on lancelets and lampreys, and to Mr. George Clark, Secretary of Stanford University, for assistance of various kinds, notably in the preparation of the index. To Dr. Theodore Gill, he has been for many years constantly indebted for illuminating suggestions, and to Dr. Barton Warren Evermann, for a variety of favors. To Dr. Richard Rathbun, the writer owes the privilege of using illustrations from the "Fishes of North and Middle America" by Jordan and Evermann. The remaining plates were drawn for this work by Mary H. Wellman, Kako Morita, and Sekko Shimada. Many of the plates are original. Those copied from other authors are so indicated in the text.