THIS newly published manual of zoology is a translation of the author's work, which was published in Danish in 1888. It is written from the modern standpoint, dwelling rather on the embryological and structural details of the forms of animal life, and using the scheme of classification as a subject of secondary importance. While the present volume is based on the author's previous work, it is no mere translation; not only is there a quite new chapter added under the heading of “Biology,” in which the distribution of animals on land, sea, and fresh water, parasitism, non-locomotory animals, and such like subjects are briefly discussed, but changes have been made in the species of animal forms selected for illustration when those previously selected would not have been easily attainable by the German student. New figures have been introduced, and the work has generally been revised. The author warmly thanks Prof. Spengel, of Giessen, for much help rendered in the revision of the translation, German not being Dr. Boas's mother tongue. The first portion of this manual treats of the cells and tissues, the various organs or systems, development, and phylogeny, and includes the chapter above-mentioned on biology, and on the distribution of animals in space and time. The special portion treats of the classes of animals, from the Protozoa to Mammalia. Certain groups, the position of which is uncertain, are treated as “appendages” to the larger ones, such as the Sponges to the Cœlenterates, the Tunicates to the Vertebrates, &c. Possibly, from the student point of view, this is going too far afield. Another point that struck us in a perusal of this volume was the absence of all references to the work of others in the field of zoology. We are very far from suggesting that it would be desirable to refer, in a necessarily compressed statement of facts, to the first discoverer of, or recorder of, the same; but there have been some epoch-making discoveries, such as have revolutionized our ideas of development, structure, and classification, and we think it a good plan to let the student know the names of the authors of these, as we fancy that, by doing so, the facts are all the more impressed upon his mind. In some few cases we would even go further, and, by telling the student where to look for further details, try and interest him in bibliography. It may be as well to add that in an indirect way this reference to the labours of others is, in a few instances, made in this volume, for some of the illustrations are inscribed as “after Allmann, Huxley, Weismann, Sars,” &c.