IN this volume the author “has endeavoured to collate materials which will serve as a class-room text and reference work,” assuming that the student has already had an introductory course in zoology. The attempt to compress an account of the invertebrates into 240 pages is, in our opinion, scarcely successful, for it has compelled the author to deal so summarily with many of the subjects and of the classes that the accounts are too short and inadequate to be of real value; e.g., endo-mixis is dealt with in about eight lines, and the student can form little idea of the process from a perusal of this brief statement. It would have been better, we think, to omit reference to a number of the more difficult groups, e.g., Phoronida (the account of which occupies about eight lines), and deal more fully with other groups. Some of the references to protozoa require revision, e.g., that Piroplasma hominis is the causal agent of Rocky Mountain fever, and the use of “hsemogre-garines “as synonymous with Babesia is incorrect. If a cyst of E. histoly-tica is to be illustrated at all, a figure better than Fig. 24 should have been provided. We can only conclude that in a course in which such a compressed account of invertebrates is used, it is intended that much of the information on any given group will be acquired in the laboratory, the text-book serving as a brief summary for reference.