office at the last change of cars, but could not think where I was going, yet I had lived in the town 16 years.

There are a few instances given in which loss of memory is due to distraction. A middle aged woman heard of her son's death by drowning. She could not remember her husband's address in order to telegraph him, although she had written there hundreds of times. "Aunt recalls nothing that happens since her husband's death."

Defective memory in children is ascribed to things known. There are many instances reported in which forgetting occurred in the field of things done, many of these cases, however, are evidently cases of temporary forgetfulness due to abstraction. All of the Indians, with a single exception, state that things known are most easily forgotten. As to abstraction, no period of life is free from its influence. Not a few draw comfort from the facts frequently cited, that Samuel Johnson, when he had stepped from the sidewalk would continue for a long distance with one foot in the gutter and one on the walk; that Pestalozzi did not know enough to put up his umbrella when it rained; that Sir Isaac Newton supposed he had eaten when he saw the chicken bones on his plate; and that Edison forgot his wedding day. Still the fact remains that no period of life is free from noticeable abstraction. The boy with book in hand forgets to go to dinner after he has rung the bell; the young woman goes to different parts of the house, she knows not why; middle age hunts for the thimble on its finger, or the pen in its mouth; while old age is troubled that it cannot find the glasses on its nose.

Loss of mind and heredity are much less frequently cited as causes of forgetfulness than abstraction or distraction due to disease.

The fourteenth question was very abstract, and in some instances was evidently misunderstood. The answers came chiefly from young people. Of those who apparently answered in an intelligent manner 140 believed that the interval between being aware of an experience and the ability to define, locate and name the experience grows narrower as we grow old. Often the period up to middle age only is considered. One qualifies the statement" until old age;" two state that this is true until college is reached; while many consider that it holds until middle age. Not a few of the replies are the outgrowth of individual experiences, and would not apply after the age of 20 or 22 is reached. 125 state that the interval grows wider. Several state that this is especially true of middle age. The fact is recognized in the returns that the interests of middle life are greater, and the range of one's acquaintances is wider, and that this influences the interval necessary for recognizing and

defining an experience. This may not be the only factor, but it seems to offer, at least, a partial explanation. A fruitful field of inquiry is thus opened up and the ground broken. Prolonged and painstaking study of this problem may be richly repaid.

The writer acknowledges his indebtedness to President G. Stanley Hall for his unremitting interest and helpful suggestions, to Dr. E. C. Sanford for practical plans as to working up the returns, and to Dr. Burnham for criticism. He is deeply indebted to the many educators in colleges, normal schools, academies and high schools, for returns sent to the questionnaire. Their unselfish work remains as a most pleasing recollection. Mention must be made of Miss Lillie A. Williams, of the Trenton (N. J.), Normal School, for a great amount of excellent work; also of Miss Sarah W. Smith, of Medina, Ohio. A large number of papers were sent by President A. H. Heineman, of Haskell Institute, Ks., President Charles Meserve, of Raleigh, N. C., and by Booker T. Washington, of Tuskegee, Ala.

METHODS IN ANIMAL PSYCHOLOGY.

By LINUS W. KLINE, PH. D.

The differentiation of comparative psychology, as a branch and method to general psychology, has been comparatively slow. Its growth, however, has been natural and healthy, and its contributions to the study of mind are ever increasing in value. A complete historical account of this differentiation would be quite premature; yet it may be worth while to note in passing that several of the special problems of psychology,-for example: emotions, instinct, habit, heredity, etc., have been treated on very broad lines by such all-around scientists as La Marck, Brehm, Darwin, Kingsley, Wallace and Agassiz. A little later, men like Naegal, Huxley, Romaines, Lubbock, Graber, and Spalding, began to focus down and make experiments and observations on the senses, habits and intelligence of animals. Running somewhat parallel with these two groups of more purely scientific writers are the speculative and philosophic pens of Oken, Lewes, Spencer, Schneider, Weismann, Büchner, Cope and others who have evaluated and ennobled the facts of organic life by indicating their significance on the more serious and time-honored problems of mind and philosophy.

1

At present, definite problems, as the formation of association processess, imitation, habit and instinct, are put to animals by playing upon some one or more fundamental instincts and taxic motions like those of hunger, sex, discomfort in solitude and prison, preferences for certain colors, geotaxis, chemotaxis, tonotaxis, etc. The ablest representative for psychology in this work is Lloyd Morgan, whose careful and critical interpretations of the objective manifestations of mind through bodily activities have done much to make comparative psychology reputable as a science, and even now essential to a comprehensive understanding of the more fundamental problems of mind. Wundt likewise has criticised to great advantage the usual erroneous and loose interpretations of animal activities. Criticisms of this type should not cease yet awhile.

The matter of interpretation at this stage, however, it seems to me is secondary. The most urgent need at present is more and better methods to get at the facts, which, when once discovered, will receive ample and proper attention.

Thorndike, Edward L.: Animal Intelligence. An experimental study of the associative processes in animals. N. Y., June, 1898.

The systematic study of animals thus far has been conducted along two lines: oue, for a better name, we shall call the natural method. This consists in observing carefully and continuously the free life of an animal, for example: Huber, Moggridge, and McCook on ants, Audubon on birds, Figuier on insects, Mills' on our domestic animals; the second line of work may be termed the experimental method. Here the animal is subjected to certain conditions essential in putting a question, and that favor the performance of activities that shall contribute material for answering a problem.

Both methods are necessary to a more abundant ingathering of facts. Both are frequently used by the same investigators, e. g., Lubbock and Bethe' on ants, and Morgan on birds. Both have their share of errors and abuses. In the natural methods the cleverness of animals is sometimes overestimated, anecdotes of a questionable foundation are given too much credence. In the experimental method, conditions too artificial are liable to be created, thereby inhibiting the free expression of the animal's Fear is too often present, dominating and modifying every act. A recent investigation makes exclusive use of the second method, which seems to me exposes the results to serious criticism. I shall revert to this investigation later in this paper.

acts.

Partly as an illustration of the use of these two methods combined, partly to reinforce observations already made, and lastly to present a bit of new material, I present the results of experiments and observations made on vorticella, wasps, chicks and

rats.

3 VORTICELLA GRACILIS.

The object here was to discover what activities, if any, have a psychological significance or value. The activities may be subsumbed under the following rubrics: Self-preservation, reproduction, and "miscellaneous." The first includes all those movements, whatever, both of the whole and parts of the cell, exerted in food-getting, ejecting detritus, placing the mouth in a more advantageous position for receiving food, contracting the stalk to escape an enemy, or when cilia touch any large body, dead or alive, etc.

The reproductive activities need no specification. Miscellaneous activities include all those movements for which we can

1 Mills, Wesley: Animal Intelligence. 307 pp. The Macmillan Co., 1898. Bethe, Albrecht: Dür fur wirden Ameisen und Biemen psychische Qualitäten zuschreiben? Pflüger Archiv für Physiologie. Bd. LXX 1898.

I am greatly indebted to Dr. C. F. Hodge for many valuable suggestions in carrying out this experiment.

assign no cause, e. g., violent contraction of the stalk at a time when the field is free from any disturbing element that might be revealed by the microscope, food abundant, and body fairly well filled. Probably a study directed with a view to ascertain its chemotaxic and tonotaxic reactions would make some of these activities meaningful. I turn to the activities of self-preservation and note first the movements of the body as a whole. If the long axis of stalk and calyx is in and with a current of water,' the calyx is soon turned across the stream, forming an angle with the stalk. It is evident, owing to the well-known bell-shape of the calyx and the position of the cilia, that thus turning the bell would greatly facilitate food getting. Is there a psychical element in such a movement, i. e., is the movement the outcome of the exercise of a psychical force? It appears to me that an affirmative answer is open to two serious objections: First, it can be explained in several other equally as plausible terms. The reaction to hunger alone is sufficient to account for the movement, and when we reflect that the habitat of V. is on grasses bathed by currents, natural selection might well be invoked as the principle that has impressed a reflex or mechanical movement of this sort on the cell. Then again, the inequality of the density of the current on the sides of the bell is a stimulus sufficient to cause a reaction expressed in movement (tonotaxis). Reactions of this sort occur in paramœcia, hydra, frog, and the human conjunctive; second, to ascribe a directing role to whatever psychoses that may be present in these forms to activities of this sort, precludes further investigation-just as the "fiat creation hypothesis" of the middle ages kept men from enquir ing into the more rational ways of world growth.

The mouth cilia are so directed as to either receive or reject small particles of matter. These activities have been championed as psychical. That the cilia do these things there can be no question, but that they are movements directed by a psychosis, i. e., are really selective, expressing choice, is quite another question. Before this question can be scientifically discussed, it seems to me another question must first be determined, viz.: Have vorticellæ a choice in food-do they not

1A current of sterilized water carrying yeast cells from a large flask was kept flowing under the cover slip. The water was drawn from the flask through a glass syphon, down to a capillary point, placed at one end of the cover slip, and a filter-paper drip attached to the other end. The microscope used was a Zeiss, apochromatic series, comp' ocular 12 objective 16 mm., which gave a magnification 190 diameters, and sometimes ocular 6, objective 4 mm. was used-magnification 375 diameters. The vorticella were found in great abundance from flags placed in an aquarium three weeks.

Jennings, H. S.: Reaction of Ciliate Infusoria. Journal of Physi ology, Vol. 21, 1897, pp. 258-321.