the "constructs" of two "sense fields," vision and taste. The existence of this association is proved by its effectiveness in subsequently bringing about, with only one stimulus presented, the same reaction against a natural positive heliotropism, as previously occurred with two stimuli present. The reaction here is therefore conditioned internally, as well as externally. The internal condition must be identical with either the excitation of, or with that and the reproduction from the "after-effect" of the second, the taste-stimulus;" if there is only excitation then the internal event is only physiological; if there is also reproduction then it is psychical as well as physiological.

Both interpretations agree equally well with the data obtained, for the reason that even in the second case there must be a physiological basis for the psychical events if present, and consequently, the two being quite compatible as ultimately regular and uniform series of events, there is theoretically no certain objective criterion for the presence here of consciousness.

Practically there is, however, such an objective criterion. which we make use of in our intercourse with other men, and if the above data are interpreted in as strict analogy to this as possible, it seems justified to consider that the Hermit Crab "reproduces" or, if one will, remembers vaguely.

The author, as a holder of one of its "research rooms" at Woods Hole wishes to acknowledge his indebtedness to the Carnegie Institution for the opportunities thus presented for the carrying on of this and other investigations.

Jan. 12, 1904.

EDITORIAL.

L' ENVOI.

The change recently announced and, by the appearance of this number, placed in process of realization means much to the writer. It means, among other things, the fulfillment of a cherished desire and the realization of hopes which led to the founding of the Journal of Comparative Neurology at a time when the prospect of either scientific or material support seemed very small. The small but growing band of investigators in this country were much better than their promise in supplying material and in supporting the enterprise from the start. In spite of the fact that the specific purpose of the venture was realized only in part, a fact partly to be accounted for by the long-continued incapacity of the writer, it is believed that the thirteen years of the existence of the Journal have not been entirely unfruitful.

It seems not inappropriate that the writer should avail himself of this occasion, apparently so full of promise for greater usefulness in the future, to express his personal gratitude for the unselfish toil which has been expended by the numerous collaborators on the staff during a period of nearly ten years, during which care on his part has been impossible and his own responsibility of the most perfunctory kind. To my brother, Professor C. JUDSON HERRICK, especially, who has carried the administrative and editorial responsibility, much of the time with little or no assistance, and on whom the financial burden has too largely fallen, the Journal owes its continued existence and the new lease of life to which we now look hopefully forward. Thanks are due also to the many others, both in this country and abroad, who have actively shared in the responsibilities

and have contributed from their original material, as well as to the numerous friends who at this emergency have contributed money to enable us to enlarge at once, pending the substantial increase in circulation which is already in progress.

At the time the earlier numbers were issued there was little of that camaraderie and acquaintance among the widely scattered workers in this, as in many other lines, which now is one of the pleasant and encouraging features of scientific work. With a growth of this fellowship we note with gratification the almost entire disappearance of the acrid or acrimonious criticism that disfigured early scientific literature in America. It is now possible to admit differences of opinion or to detect errors in the work of another without establishing forthwith a breach of cordial relations among the workers. C. L. HERRICK.

Structure and function are correlative concepts; neither is complete without the other; as cause implies effect, so function implies structure. These are trite statements, yet it would seem that we can not be reminded too often that the understanding of life is dependent upon our ability to correlate structural and functional facts. It is chiefly in the interest of such correlation that The Journal of Comparative Neurology and Psychology is published. True, there is no more reason for considing the psychic process a function of the nervous system, than for calling the brain a function of consciousness; but, this aside, animal behavior and the functions of the sense organs and central nervous system are dependent upon neural structures, and it is these which most concern us. A survey of modern research literature shows clearly that those investigators have been eminently successful who have studied structure and function at the same time. To the physiology of the senses vastly more is contributed by those who know form as well as function, than by those who neglect anatomical conditions; in animal behavior, it is from the student who attends to anatomical and histological facts that a satisfactory account of the reactions of an organism is to be expected.

Throughout the organic realm a correlation of structure and function is demanded. It is our aim, in The Journal of Comparative Neurology and Psychology, to bring together anatomical, physiological and psychological facts in such a manner that their relations may appear. Thus, it is hoped, the specialists in structural work will be impressed by the importance of the functions of the organs which they study, while at the same time those whose chief concern is animal behavior will see more clearly that they cannot work to advantage unless they know what is functioning. If we are to understand life we must consider the organism not as a structural unit, nor yet as a sum of activities, but as a functioning structure.

R. M. YERKES.

THE MID-WINTER MEETINGS.

Though abstracts of the proceedings of most of the socie; ties which met during convocation week have already been published, it may be of interest to enumerate in a single list the more important papers read which bear upon our problems, as an aid to the annual invoice of scientific achievement which one naturally makes at this time of year.

At St. Louis the zoological section of the American Association and the Central Branch of the American Society of Zoologists held joint sessions at which the following papers of neurological interest were read:

Further Observations on the Breeding Habits and on the Functions of the Pearl Organs in Several Species of Eventognathi, by JACOB REIGHARD. The breeding habits of certain shiners and suckers were described and illustrated by instantaneous photographs.

Phototaxis in Ranatra, by S. J. HOLMES. Ranatra is positively phototactic and a great variety of reactions can be produced at will with mechanical precision.

The Correlation of Brain Weight with Other Characters, by RAYMOND PEARL. A statistical review of the data for the human brain.

The Morphology of the Vertebrate Head from the View-point of the Functional Divisions of the Nervous System, by J. B. JOHNSTON. This paper will appear in full in this Journal in the course of the current year.

The Brain and Nerve Cord of Placobdella pediculata, by E. E. HEMINGWAY. Wax models of the nervous system of this new leech were presented. The results in general confirm those of WHITMAN for Clepsine.

The Mechanism of Feeding and Breathing in the Lamprey, by JEAN DAWSON. The anatomical work was controlled by observations on the living animals which add to our knowledge of the habits of the species, notably the fact that the lamprey feeds on the soft tissues as well as the blood of its host.