Comparative Physiology of the Brain and Comparative Psychology

that simultaneous simple harmonic motions may in our sensations fuse to a compound sound of definite character (Klangfarbe). Moreover, a trained ear is able to decompose a compound Klang into its simple harmonic constituents. The mechanism of associa- tive memory must share these peculiarities of our organs for the perception of sounds. I believe that what we commonly call intelligence depends partly upon the development of this power of resonance of the mechanism of association.

The existence of phenomena of resonance in our nervous processes may account for the fact that stim- ulation of the same organ yields entirely different results if we change the character or rhythm of stim- ulation. Only certain sounds cause a dog to howl ; only a certain way of rubbing the skin of a frog causes the animal to croak. The so-called law of the specific energy of the sense-organs has pushed these important facts into the background and has tried to convey the idea that the character of the stimulation was something indifferent. Although it is true that a blow on the eye gives rise to a sensation of light, nobody would for one instant mis- take this light-sensation for one caused by ether-vi- brations. It is of course impossible to throw light on this subject from the anatomy or histology of the brain. But our experiences in regard to sound-sensa- tions promise the possibility of an analysis of these phenomena. Hermann and Mach come to the con- clusion that the physical resonance-theory of Helm-

holtz is no longer tenable, and that it may have to be substituted by a physiological resonance-theory (6, 7). According to Hermann, we may assume that the nervous end-organs themselves are especially sens- itive for stimuli of a definite period (7). A gen- eralisation of this assumption would lead to an understanding of the above-mentioned fact. The motor organs of the larynx may be considered as resonators, and this would explain why only cer- tain tones cause a dog to howl and why only fric- tion of a certain character — i. e.t periods --causes a frog to croak. The fact of the easy transmission of sounds into innervations to the larynx in human beings and parrots or song-birds would depend on the same principle. But in theories of this character we must leave some leeway for the influence of chem- ical processes. The phenomena of correlation which we notice in many animals during the period of heat may be determined by substances circulating in the blood during that period (internal secretion). This may account for the change in the irritability during that period.

5. Our space-sensations are varieties of three dimen- sions. The main coordinates show a definite relation to the main axes of our body. This leads us to a consideration of the possibility whether certain struct- ural conditions of our body determine the main coor- dinates of our system of space-sensations. Hering has shown that the motor innervations of our eyes may be reduced to three kinds, corresponding to the main axes of our body : (i) innervations to move our eyes from right to left, or vice versa ; (2) innervations to move them up and down ; and (3) move them from a near to a far object, or vice versa (8). The first motion takes place along the transverse axis, the second along the longitudinal, and the third along the dorso-ventral axis. The experiments on the hori- zontal semicircular canals of the ear show that the stimulation of this canal produces motions of the eyes, head, or even of the whole animal in the plane of this canal. Our experiments on galvanotropism indicate the existence of a simple relation between the orien- tation of certain motor elements in the central nerv- ous system and the direction of the motions produced by their activity. This is supported to a certain extent by the experiments on the crura cerebelli. It thus seems possible that simple geometrical relations of structure are responsible for the fact that all our innervations may be reduced to three classes deter- mined by the main axes of our body. On the other hand, Mach furnished the proof that the will or the process of innervation for a motion is of the same character as the process of space-sensations (5, 6). The will to move our eyes to a certain point and the space-sensation itself can be added algebraically. The experiences derived from space illusions caused by imperfect motility of the eyes or hands agree with this view. Moreover, Mach has proved that we recog- nise the geometrical symmetry of two figures very easily only when the axis of symmetry coincides with

that of our body (5, 6). All these facts indicate that the main coordinates of the physiological space are determined by structural peculiarities of our body. The ultimate structural elements in this case are not necessarily of a morphological or histological order. They may be, as Mach has intimated in another con- nection, the stereochemical configuration of certain molecules (i). As it is not my intention to enter here upon a discussion of the nature of the space- sensations, but to indicate what place they may oc- cupy in a future mechanics of the activity of the brain, these hints may suffice.

2. LOEB, J. Zur Thcoric der physiologischen Licht-und Schwer- kraft-Wirkungen. PfliigersArchiv, Bd. Ixvi., 1897. 3. LOEB, J. Muskelthdtigkeit als Maass psychischer Thdtigkeit. Pfliiger's Archiv, Bd. xxxix., 1886. 4. WELCH, J. C. On the Measurement of Mental Activity through Muscular Activity, etc. The American Journal of Physiology, vol. i., 1898. 5. MACH, E. Contributions to the Analysis of the Sensations. Chicago, 1897. 6. MACH, E. Die Analyse der Empfindungen und das Verhdlt- niss des Physischen zum Psychischen. Jena, 1900.

7. HERMANN, L. Beitrdge zur Lehre von der Klangwahr- nthmung. Pfliigers Archiv, Bd. Ivi., 1894. 8. HERING, E. Die Lehre vo m binocularen Sehen. Leipzig, 1868. — relation to instincts, 196 Associative memory. See Associa- tion. Chemical irritability in Actinians, 50 ; in earthworms, 88, 90 ; in crusta- ceans, 1 1 8. See also Chemo tropism. Darwinian views, 232, 253 Depth-distribution of marine animals, — localisation of. See Associations. Ions and rhythmical contraction, 9,

Heliotropism. Limulus, 102-113 Lingle, 28 Localisation, psychic and anatomical, Muscular activity, a measure of men- tal activity, 294, etc. — without ganglion, 35-46 Respiration, in relation to ganglia, — in Tubularia, 184 Stinging reflex of bees, 123 Subctsophageal ganglion in annelids, "A timely and useful volume. . . . The author wields n pleasing pen and knows how to make the subject attractive. . . . The work is calculated to spread among its readers an attraction to the science of anthropology. The author's observations are exceedingly genuine and his descriptions are vivid." — London Atkenteunt.

"The book is cleverly written and is one of the best works of its kind ever put before the public. It will be interesting to all readers, and especially to those interested in the study of science." — New Haven Leader, 3. — Rivers of North America. A Reading Lesson for Students of Geo- graphy and Geology. By ISRAEL C. RUSSELL, Professor of Geology, University of Michigan, author of " Lakes of North America," " Gla- ciers of North America," '* Volcanoes of North America," etc. Fully illustrated. 8°, net $2.00.

" There has not been in the last few years until the present book any authoritative, broad resume on the subject, modified and deepened as it has been by modern research and reflection, which is couched in language suitable for the multitude. . . . The text is as entertaining as it is instructive." — Boston Transcript. 4. — Earth Sculpture ; or, The Origin of Land-Forms. By JAMES GEIKIE, LL.D., D.C.L., F.R.S., etc., Murchison Professor of Geology and Mineralogy in the University of Edinburgh ; author of " The Great Ice Age," etc. Fully illustrated. 8°, net $2.00.

"This volume is the best popular and yet scientific treatment we know of of the ori- gin and development of land-forms, and we immediately adopted it as the best availablo text-book for a college course in physiography. . . . The book is full of life and vigor, and shows the sympathetic touch of a man deeply in love with nature." — Science. 5.— Volcanoes : Their Structure and Significance. By T. G. BONNEY, F.R.S., University College, London. Fully illustrated. 8°. Revised and Enlarged Edition. Illustrated. Net $2.00.

" It is not only a fine piece of work from a scientific point of v:»w, but it is uncom- monly attractive to the general reader, and is likely to have a larger sale than most books of its class."— Springfield Republican. 6 Bacteria : Especially as they are related to the economy of nature, to industrial processes, and to the public health. By GEORGE NEWMAN, M.D., F.R.S. (Edin.), D.P.H. (Camb.), etc., Demonstrator of Bac teriology in King's College, London. With 24 micro-photographs of actual organisms and over 70 other illustrations. 8°, net $2.00.

"*Dr. Newman's discussions of bacteria and disease, of immunity, of antitoxins, and of methods of disinfection, are illuminating, and are to be commended to all seeking in formation on these points. Any discussion of bacteria will seem technical to the uniniti ated, but all such will find in this book popular treatment and scientific accuracy happil? combined."— The Dial. ** Mr. Beddard has done well to devote a whole volume to whales. They are worthy of the biographer who has now well grouped and described these creatures. The general leader will not find the volume too technical, nor has the author failed in his attempt to produce a book that shall be acceptable to the zoologist and the naturalist." — N. Y. Times

6. -Comparative Physiology of the Brain and Comparative Psy- chology. With special reference to the Invertebrates. By JACQUES LOEB, M.D., Professor of Physiology in the University of Chicago. Illustrated. 8°. Net, $i-75- " No student of this most interesting phase of the problems of life can afford to remain in ignorance of the wide range of facts and the suggestive series of interpretations which Professor Loeb has brought together in this volume." — JOSEPH JASTROW, in the Chicago Dial.

9. — The Stars. By Professor SIMON NEWCOMB, U.S.N., Nautical Al- manac Office, and Johns Hopkins University. 8°. Illustrated. Net, "The work is a thoroughly scientific treatise on stare. The name of the author is sufficient guarantee of scholarly and accurate work." — Scientific American. 10.— The Basis of Social Relations. A Study in Ethnic Psychology. By DANIEL G. BRINTON, A.M., M.D., LL.D., Sc.D., Late Professor of American Archaeology and Linguistics in the University of Pennsyl- vania ; Author of " History of Primitive Religions," " Races and Peoples," " The American Race,** etc. Edited by LIVINGSTON FAR- RAND, Columbia University. 8°. Net, $1.50

" Professor Brinton his shown in this volume an intimate and appreciative knowledge of all the important anthropological theories. No one seems to have been better acquainted writh the very great body of facts represented by these sciences." — Ant. "Journal of Sociology. ii. — Experiments on Animals. By STEPHEN PAGET. With an Intro- duction by Lord Lister. Illustrated. 8°. Net, $2.00. "To a large class of readers this presentation will be attractive, since it gives to them in a nut-shell the me<it of a hundred scientific dissertations in current periodical literature. The volume has the authoritative sanction of Lord Lister." — Boston Transcript.

12, — Infection and Immunity. With Special Reference to the Prevention of Infectious Diseases. By GEORGE M. STERN BERG, M-D., LL.D. Surgeon-General U. S. Army (Retired). Illustrated. 8°. Net, $1.75. •* A distinct public service by an eminent authority. This admirable Jittte work shonH b* a part of the prescribed reading of the head of every institution in wliirh children of vouths are gathered. Conspicuously useful." — N. Y. Times. 13.— Fatigue, By A. Mosso, Professor of Physiology in the University of Turin. Translated by MARGARET DRUMMOND, M.A., and W. B. DRUMMOND, M.B., C.M.,F.R.C.P.E.;extra Physician, Royal Hospital for Sick Children, Edinburgh ; Author of " The Child, His Nature and Nurture." Illustrated. 8°. Net, $1.50.

" A book for the student and for the instructor, full of interest, also for the intelligent general reader. The subject constitutes one of the most fascinating chapters in the his- tory of medical science and of philosophical ieieaich.'"—yor&sAire Post. "The book sumni.iri/cs the results of the men who have accomplished the Rre.it things in their pursuit of si ismolo^ical knowledge. It is alnnid.intly illustrated and it fills a place uniijue in the literature o( modern science. "--Chicago Tribune.

15. — The Nature of Man. Studies in Optimistic Philosophy. By ELIE MKTCHNIKOKK, Professor at the Pasteur Institute. Translation and introduction by P. CHAMBERS MITCHELL, M.A., D.Sc. Oxon. Illus- trated. 8°. Net, $1.50. 11 A hook to he set side by side with Huxley's Essays, whose spirit ,'t carries a st>-p further un the long road towards its goal." — Mail and Express. 16. — The Hygiene of Nerves and Mind in Health and Disease. By Ar<;rsT FORM,, M.D., formerly Professor of Psychiatry in the Uni- versity of Zurich. Authorized Translation. 8°. Net, $2.00.

A comprehensive and concise summary of the results of science in its cnosen field. Its authorship is a guarantee that the statements made are authoritative as far as tht statement of an individual can be so regarded. T7.— The Prolongation of Life. Optimistic Essays. By ELIE METCH- NIKOIF, Sub-Director of the Pasteur Institute. Author of 'The Nature of Man," etc. 8°. Illustrated. Net, $2.50. Popular Edition. With an introduction by Prof. CHARLES S. MINOT. Net, $1.75-

In his new work Professor Metchnlkoff expounds at greater length, in the light of additional knowledge gained in the last few years, his mam^thesis that human life is not only unnaturally short but unnaturally burdened with physical and mental disabilities. He analyzes «.he causes of these disharmonies and explains his reasons for hoping thai they may be counteracted by a rational hygiene. 18.— The Solar System. A Study of Recent Observations. By Prof. CHARLES LANE POOR, Professor of Astronomy in Columbia University. 8°. Illustrated. Net, $2.00.

The subject is presented in untechnical language and without the use of mathematics. Professor Poor shows by what steps the precise knowledge of to-day has been reached and explains the marvellous results of modern methods and modern observations. 19.— Heredity. By J. ARTHUR THOMSON, M.A., Professor of Natural History in the University of Aberdeen ; Author of "The Science of Life," etc. 8°. Illustrated. Net, $3.50. The aim of this work is to expound, in a simple manner, the facts cf heredity and Inheritance as at present known, the general conclusions which have been securely established, and Jie more important theories which have been formulated.

20.— Climate— Considered Especially in Relation to Man. By ROBERT DECOURCY WARD, Assistant Professor of Climatology in Harvard University. 8°. Illustrated. Net, $2.00. This volume is intended for persons who have not had special training in the tech- nicalities of climatology. Climate covers a wholly different field from that included in the meteorological text-books. It handles broad questions of climate in a way which h:is not been attempted in a single volume The needs of the teacher and student have beer kept constantly in mind.

21. — Age, Growth, and Death. By CHARLES S. MINOT, James Still- man Professor of Comparative Anatomy in Harvard University, President of the Boston Society of Natural History, and \uthor of "Human Embryology," "A Laboratory Text-book of Embryology," etc. 8°, Illustrated.' $2.50 net. This volume deals with some of the fundamental problems of biology, ind pre*rni» • series of views (the results of nearly thirty years of study), w>>- ' trm author hi* Correlated for the first time in systematic form.

22. — The Interpretation of Nature. By C. LLOYD MORGAN, LL.D., Dr. Morgan seeks to prove that a belief in purpose as the causal reality of which nature is an expression is not inconsistent with a full and whole-hearted acceptance of the explanations of naturalism. 23. — Mosquito Life. The Habits and Life Cycles of the Known Mos- quitoes of the United States; Methods for their Control; and Keys for Easy Identification of the Species in their Various Stages. An account based on the investigation of the late James William Dupree, Surgeon-General of Louisiana, and upon the original observations by the Writer. By EVELYN GROESBEECK MITCHELL, A.B., M.S. With 64 Illustrations. 8°. Net, $2.00.

This volume has been designed to meet the demand of the constantly increasing number of students for a work presenting in compact form the essential facts so far made known by scientific investigation in regard to the different phases of this, as is now conceded, important and highly interesting subject. While aiming to keep within reasonable bounds, that it may be used for work in the field and in the labora- tory, no portion of the work has been slighted, or fundamental information omitted, in the endeavor to carry this plan into effect.

24. — Thinking, Feeling, Doing. An Introduction to Mental Science. By E. W. SCRIPTURE, Ph.D., M.D., Assistant Neurologist Columbia University, formerly Director of the Psychological Laboratory at Yale University. 189 Illustrations. 2d Edition, Revised and Enlarged. 8°. Net, $1.75. "The chapters on Time and Action, Reaction Time. Thinking Time, Rhythmic Action, and Power and Will are most interesting. This book should be carefully read by every one who desires to be familiar with the advances made in the study of the mind, which advances, in the last twenty-five years, have been quite as striking and epoch-making as the strides made in the more material lines of knowledge." — Jour. Amer. Med. Ass'n., Feb. 22, 1908.

25. — The World's Gold. By L. DE LAUNAY, Professor at the Ecole Supe'rieure des Mines. Translated by Orlando Cyprian Williams. With an Introduction by Charles A. Conant, author of "History of Modern Banks of Issue," etc. 8°. Net, $1.75. _ M. de Launay is a professor of considerable repute not only in France, but among scientists throughout the world. In this work he traces the various uses and phases of gold; first its geology; secondly, its extraction; thirdly, its economic value.

26. — The Interpretation of Radium. By FREDERICK SODDY, Lecturer in Physical Chemistry in the University of Glasgow. Third Edi- tion, rewritten, with data brought down to 1912. 8°. With 33 Diagrams and Illustrations. $2.00 net. As the application of the present-day interpretation of Radium (that it is an element undergoing spontaneous disintegration) is not confined to the physical sciences, but has a wide and general bearing upon our whole outlook on Nature, Mr. Soddy has presented the subject in non-technical language, so that the ideas involved are within reach of the lay reader. No effort has been spared to get to the root of the matter and to secure accuracy, so that the book should prove serviceable to other fields of science and investigation, as well as to the general public.

27. — Criminal Man. According to the Classification of CESARE LOM- BROSO. Briefly Summarized by his Daughter, Gina Lombroso- Ferrcro. With 36 Illustrations and a Bibliography of Lombroso's Publications on the Subject. 8°. Net $2.00. Signora Guglielmo Ferrero's r6sum£ of her father's work on criminal anthropo- logy is specially dedicated to all those whose office it is to correct, reform, and punish the criminal, with a view to diminishing the injury caused to society by his anti-social acts; also to superintendents, teachers, and those engaged in rescuing orphans and children of vicious habits, as a guide in checking the development of evil germs and eliminating incorrigible subjects whose example is a source of corruption to others.