This is a most masterly work, indispensable to the student of fishes. Its descriptions are generally fairly correct, its plates accurate, and its judgments trustworthy. But with all this it is very unequal. Too often nominal species are based on variations due to age or sex or to the conditions of preservation of specimens. Many of the species are treated very lightly by Cuvier; many of the descriptions of Valenciennes are very mechanical, as though the author had grown weary of the endless process, "a failing commonly observed among zoologists when attention to descriptive details becomes to them a tedious task."
After the death of Valenciennes (1865) Dr. Auguste Duméril began another Natural History of the Fishes. Of this two volumes (1865-70) were published covering sharks, ganoids, and other fishes not treated by Cuvier and Valenciennes, his category beginning at the opposite end of the fish series. The death of Duméril left this catalogue also unfinished. Duméril's work is useful and carefully done, but his excessive trust in slight differences has filled his book with nominal species. Thus among the living ganoid fishes he recognizes 135 species, the actual number being not far from 40.
We may anticipate the sequence of time by here referring to the remaining attempts at a record of all the fishes in the world, Dr. Albert C. L. G. Günther, a naturalist of German birth, but resident in London for many years, long the honored keeper of the British Museum, published in eight volumes the "Catalogue of the Fishes of the British Museum," from 1859 to 1870. In this monumental work, the one work most essential to all systematic study of fishes, 6843 species are described and 1682 doubtful species are mentioned. The book is a remarkable example of patient industry. Its great merits are at once apparent, and those of us engaged in the same line of study may pass by its faults with the leniency which we may hope that posterity may bestow on ours.
The publication of this work gave an immediate impetus to the study of fishes. The number of known species has been raised from 9000 to about 12,000 in the last thirty years, although meanwhile some hundreds of species even accepted by the conservatism of Günther have been erased from the system.
A new edition of this work has been long in contemplation, and in 1898 the first volume of it, covering the percoid fishes, was published by Dr. George Albert Boulenger. This volume is one of the most satisfactory in the history of ichthyology. It is based on ample material. Its accepted species have been subject to thorough criticism and in its classification every use has been made of the teachings of morphology and especially of osteology. Its classification is distinctly modern, and with the writings of the contemporary ichthyologists of Europe and America, it is fully representative of the scientific era ushered in by the researches of Darwin. The chief criticism which one may apply to this work concerns most of the publications of the British Museum. It is the frequent assumption that those species not found in the greatest museum of the world do not really exist at all. There are still many forms of life, very many, outside the series gathered in any or all collections.
Albert Günther.
Franz Steindachner.
George A. Boulenger.