part similar to the food, water and other necessary conditions of the environment: diversities in it are held not to produce hereditary diversities in the offspring. Whether the theory is correct or not is a purely experimental question; certainly the evidence for it is very strong for most organisms. Ritter's argument consists in setting forth in great length and detail the fact that the cytoplasm takes part in the formation of all the structures produced; a fact of course familiar to all students of genetics, but having no bearing on what they mean by the theory that the chromosomes are the bearers of the hereditary qualities. It might be argued of course that in meaning this they misuse words, but it is a pity to mistake difference of opinion as to linguistic fitness for one as to the facts of inheritance. To the reviewer the critical and condemnatory parts of these volumes appear much less valuable than the expository and constructive portions.
In sum, the reviewer anticipates that many biologists will be found friendly to the propositions set forth in our subdivisions 1 to 4, but that there will be much dissent as to the value of many of the matters set forth under 5; and that there is little likelihood of any considerable change in scientific procedure in view of the points made.
H. S. Jennings.
Johns Hopkins University.
This book by the Professor of Logic and Metaphysics at the University of Aberdeen is made up of an Introduction and nine 'Studies' or essays with the following titles: (I) Anthropomorphism and Truth; (II) The Realistic Character of Knowledge; (III) Certain Non-Logical Factors in the Process of Knowledge; (IV) The Nature of Memory-Knowledge; (V) The Function of Emotion in the Consciousness of the Real; (VI) The Significance of Philosophical Scepticism; (VII) The Place of Philosophy in Human Nature; (VIII) Science and the Humanities; (IX) Laughter and Tears: The Sense of Incongruity.
The philosophical standpoint from which the book is written is indicated in a general way by the title of the book and by certain statements in the preface. "It is not the purpose of these papers," the author writes, "to defend or support any of the familiarly accepted theories, whether of idealism or realism. Human nature is far
