[99] Mr. Gordon Rett has recently called my attention to a blind "angel fish" which shows, most conspicuously, a lack of tinctumutation. This fish was made blind for experimental purposes.—W.

[100] Karl Semper, Animal Life, pp. 95, 96.

Pouchet cut the spinal cord close to the brain, yet the chromatophores still responded to light impression, showing that they did not receive the message through the cord and spinal nerves. He then divided the sympathetic nerves, and the chromatophores lost at once the power of contraction; he thus demonstrated that the sympathetic nerves were the transmitters of the optical message, and not the cord.

This discovery of Pouchet is, psychologically, of great importance, though he failed to recognize it as such. He was satisfied with its anatomical and physiological significance.

When we remember that the actions of the sympathetic nerves are almost, if not entirely, reflex in character, we at once see the psychological importance of this discovery. This fact makes the phenomenon of tinctumutation an involuntary act on the part of the animal possessing the chromatic function, and thus keeps inviolate the fundamental laws of evolution, which, were the facts otherwise, would be broken.[101]

[101] This simple fact of involuntary action renders the sensual nature of the function all the more apparent.—W.

By a series of experiments on frogs I have confirmed the conclusion of Pouchet in toto, and have even solved, so I believe and unhesitatingly assert, the puzzling problem of the physiological modus operandi of the wonderful phenomenon of tinctumutation.

For a very long time I believed that this function was a distinct sense, and, five years ago, I set to work in search of the sense's centre. After many dissections I found it (in the frog) lying immediately below the optic centres and closely connected with them. Nerve-fibres of the sympathetic can easily be traced and can be seen to penetrate this centre. When this centre is artificially stimulated either with the point of a needle or with a mild electric current, tinctumutation can be incited at will.

Again, when this centre is destroyed (which can be done without injury to the optic centres), the chromatophoric function ceases—the phenomenon of tinctumutation is no longer observable.

That the sympathetic nerves are the carriers of the messages from the optic nerve and the color-changing centre, can be demonstrated by other means than by excision of the nerve. Atropine, to a certain extent, paralyzes the sympathetic when given in sufficiently large doses, and injections of this drug beneath the skin of a frog render the division of the sympathetic unnecessary. The chromatophores will not respond to light impressions if the animal be placed thoroughly under the influence of atropine.

A large number of the lower animals possess the chromatophoric function. Several years ago, I placed in a large cistern several specimens of gilt catfish. This is a pond fish and is quite abundant throughout the middle United States. It is of a beautiful golden yellow color on the belly and sides, shading into a lustrous greenish yellow on the back and head.

Several months after these fish had been placed in the cistern, it became necessary to clean the latter, and the fish were taken out. They were of a dusky drab color when first taken out, but soon regained their vivid tints when placed in a white vessel containing clear water. They had evidently changed color in order to harmonize with the black walls and bottom of the cistern.

Certain katydids are marked tinctumutants. I took one from the dark foliage of an elm and placed her on the lighter-colored leaves of a locust. She could be easily seen when first placed on the locust; in a few moments, however, she had faded to such an extent that she was barely noticeable.

The larvae of certain moths, beetles, and butterflies also possess the chromatophoric function. The chromatophores in the larva of Vanessa are very numerous, and this grub is a remarkably successful tinctumutant; the same can be said of the larvae of certain varieties of Pieris.

The power of changing color so as to resemble, in coloring, surrounding objects is evidently one of Nature's weapons of defence. In some animals it is developed in a wonderful manner. Wherever it is found it becomes to the animal possessing it a powerful means of defence by rendering it inconspicuous, and in some instances wholly unnoticeable.

After nine years of careful, systematic, and painstaking investigation, I am prepared to affirm that, besides the senses, sight, smell, taste, touch, hearing, and tinctumutation, certain animals have yet another sense, the sense of locality, or of direction, commonly called the "homing instinct." This remarkable function of the mind is not an instinct any more than the sense of sight or smell is an instinct, but is, on the contrary, a true sense; for I have demonstrated by actual experiment that it has a centre in the brains (ganglia) of some of the animals possessing it, just as the other senses have their centres. And, since this centre has been found in certain species, and that, too, in creatures very low in the scale of animal life, it is reasonable to infer that it is present in the brains (ganglia) of all those animals which evince the so-called "homing instinct."

In the process of civilization certain of the five senses in man become dull and blunted; thus, the sense of smell in the Tagals of the Philippine Islands is much more acute than it is in the civilized European, and what is true of the sense of smell is also true of the other senses, save that of touch, in all primitive peoples. This last sense seems to be much more acute in civilized man than it is in savages. This, for certain psychical reasons, unnecessary to detail here, is a necessary result of evolutionary growth and development.[102]

[102] Compare Tyler, Anthropology; De Quatrefages, The Human Species; Peschel, The Races of Man; Lombroso, L'Uomo Delinquente; Ellis, The Criminal; the writer, "Criminal Anthropology," N. Y. Medical Record, January 13, 1894.

As far as I have been able to learn, after much research in natural history, the anthropoid apes do not show that they possess the sense of direction in a marked degree; thus we see that the immediate ancestors of pithecoid man had already begun to lose this sense, which in man is entirely wanting, and the absence of which should not be a matter of surprise in the slightest degree, but rather a result that should be expected.

Evidences of this sense are to be observed in animals of exceedingly low organization. On one occasion, while studying a water-louse, as I have already described elsewhere in this book, I saw the little creature swim to a hydra, pluck off one of its buds, then swim a short distance away and take shelter behind a small bit of mud, where it proceeded to devour its tender morsel. In a short while, much to my surprise, the louse again swam to the hydra, again procured a bud, and again swam back to its hiding-place. This occurred three times during the hour I had it under observation. The louse probably discovered the hydra the first time by accident; but when it swam back to the source of its food-supply the second time and then returned again to its sheltering bit of mud, it clearly evinced conscious memory of route and a sense of direction.

The common garden-snail is a homing animal, and it will always return to a particular spot after it has made an excursion in search of food. In front of my dwelling there is a brick wall capped by a stone coping; the overhanging edge of this coping forms a moist, cool home in summer for hundreds of snails. Last summer I took six of these creatures, and, after marking their shells with a paint of gum arabic and zinc oxide, I set them free on the lawn some distance away from the wall. In course of time, four of them returned to their homes beneath the stone coping; the other two were probably killed and eaten by blackbirds, numbers of which I noticed during the day feeding on the sward.

The centre of the sense of direction in snails is located at the base of the cephalic ganglion (brain); this ganglion lies immediately between and below the "horns" (eye-stalks), and is composed of several circumscribed and well-marked accumulations or corpuscles of nerve-cells and nerve-filaments.

This sense centre can easily be destroyed without inflicting injury on the circumjacent sense centres. Whenever this is done, the snail loses its sense of direction and locality, and cannot find its way back to its home when it is carried thence, and deposited amid new surroundings. It is not killed by the mutilation, for I have seen marked snails in which this sense centre had been destroyed, alive and apparently in good health, several weeks after having undergone this operation; they found temporary homes wherever they chanced to be.

The limpet is likewise a homing animal, and invariably returns to its home after journeys in search of food. Lieutenant L——, an officer in the British navy, once told me that he had repeatedly had specimens of this animal under observation for months at a time, and that they always had particular spots, generally depressions in rocks, which they regarded as homes, to which they would always return after excursions in search of sustenance. Romanes makes a similar statement.[103]

[103] Animal Intelligence, pp. 28, 29.

Some beetles have their homing sense highly developed; thus, in Mammoth Cave, the blind beetle (Adelops) has its particular home, and will always return to it even when it is set free at a considerable distance. Notwithstanding the fact these insects are blind, and that darkness reigns in this immense cavern, they have periods of rest corresponding with the diurnal rest-periods of kindred species living in daylight; hence, it is easy to study their habits at home and abroad.

I have frequently marked these beetles and then set them free some distance away from their domiciles; they would hide themselves at once beneath stones or clods of earth, but as soon as they had recovered from their fright they would turn towards home, and would not stop, if left unmolested, until they arrived at their particular and individual homing places. Truly a most wonderful exhibition of the homing sense!

At first, these beetles are, probably, directed and governed by their sense of direction alone, but as soon as they arrive among familiar surroundings, memory comes to their aid.

The agile flea is another "homesteader," and if marked, its favorite resting-place on a dog or cat can easily be determined. After feeding, it will invariably return to a certain spot in order to enjoy its nap in peace; for, strange as it may seem, fleas are sound sleepers, and, what is more, seem to require a great deal of sleep.[104]

[104] All insects have periods of rest, during which they seem to be in a state of slumber. Their sleep may not be the physiological slumber of mammals, yet it effects a like purpose in all probability.—W.

Ants are, of the entire insect world, probably the most gifted home-finders. Time and again have I tested them in this, sometimes taking them what must have been, to these little creatures, enormous distances from their nests before freeing them. Of course the ants experimented with were marked, otherwise I could not have watched them successfully. When an ant is taken into new surroundings and set free, it at first runs here and there and everywhere. As soon, however, as it regains its equanimity and recovers from its fright, it turns toward home. At first it proceeds slowly, every now and then climbing tall blades of grass, and from these high places viewing the surrounding country in search of landmarks. As soon as it arrives among scenes partially familiar to it, it ceases to climb grass-blades or weeds, and accelerates its pace. When it arrives among well-known and accustomed surroundings it runs along at its utmost speed, and fairly races into its nest.

The burying beetle has a regular abode, to which it invariably returns after performing the offices of mortician to some defunct bird, beast, or reptile. This insect grave-digger, by the way, is remarkably expert at its business, and will bury a frog or a bird in a very short time. As soon as it has buried the dead animal and deposited its eggs, it returns to its domicile beneath some log or stone.

Some snakes likewise are exceedingly domestic, and have their regular dens, to which they resort on occasions. The homing sense seems to be rather highly developed in them, for they can find their way back to their dens from great distances. I have had under observation for the past three years a garden snake, locally known as a "spreading viper"; this snake was brought to me by a friend[105] when it was only a foot long, so I have known her (for it is a female) ever since her infancy. Owing to some antenatal accident, this reptile has a malformed head, so that I can readily recognize her at a distance of fifteen, twenty, or even thirty feet. Last year she reared her first brood of young, which I was fortunate enough to see with her on several occasions. Her den is on my lawn; and in the autumn of last year she conducted her brood to it, where they hibernated until spring. If I remember correctly, on the 29th of March she came out of her den accompanied by a dozen of her progeny, all but four (two pairs) of which I killed.[106] Snakes subserve a very useful purpose in the economy of nature, but it is well to keep them in limits, for, when very numerous, they become dangerous to young birds, especially after they have passed the second year.

[105] Silas Rosenfield, Esq., Owensboro, Kentucky.

[106] The above was written in the summer of 1897. This interesting specimen was killed by a day-laborer who had been temporarily employed to assist the gardener. An autopsy revealed a bony tumor of the right orbital arch, which, from a little distance, looked like a horn.—W.

With the exception of the anthropoid apes all mammals possess the homing sense in a higher or lower degree; this is true also of birds. Experiments with the nesting robin show conclusively that this bird can find its way back to its nest when carried fifty miles from its home and then set free among wholly unknown surroundings. The well-known exploits of the carrier-pigeon are so familiar that they scarcely need comment. On May 3, 1898, two carrier-pigeons, en route for Louisville, rested for a time at Owensboro, Kentucky; these birds had been set free at New Orleans, Louisiana. The duck and the goose sometimes have this sense very highly developed. I once knew a goose to travel back home after having been carried in a covered basket for the distance of eighteen miles. A drake and duck have been known to return to their home after being carried a distance of nine miles by railway. Instances of home-returning by dogs, cats, horses, etc., are of such common occurrence that I hardly need call attention to them; the following instance is so unique, however, that I will present it:—

In the fall of 1861, a gentleman of Vincennes, Indiana, visited his father at Lebanon, Kentucky; when this gentleman started to return home, his father gave him a yoke of young steers, which he drove, via Louisville, Kentucky, to Vincennes.

Shortly after his arrival at this last-mentioned town, the steers made their escape, swam the river at Owensboro, Kentucky, 160 miles below Louisville, Kentucky, and, in a week or so, were found one morning at the gate of their old home at Lebanon. Directed by their homing sense alone, these animals had made a journey of several hundred miles over a route they had never seen!

Fishermen are aware that certain fish choose localities for lurking-places, which they will share with no other fish. The black bass, and brook trout, and sturgeon, and goggle-eye are familiar examples of fish which have this habit.

On one occasion, I performed the following experiment: I took a black bass from its home near a sunken stump, and, after passing a short piece of thread through the web of its tail and knotting it, replaced it in the river, two miles below its lurking-place. The next day I saw it in its old home, clearly recognizable by the bit of thread which waved to and fro in the clear water as the fish gently moved its tail!

In an examination of phenomena such as have been discussed in this chapter, ay, throughout this book, we must lay aside the dogmatic assertions of our superstitious ancestors, who, to paraphrase Roscoe, "when awed by superstition, and subdued by hereditary prejudices, could not only assent to the most incredible proposition, but could act in consequence of these convictions, with as much energy and perseverance as if they were the clearest deductions of reason, or the most evident dictates of truth."[107]

[107] Roscoe, Life of Leo X., p. 3.

It will take the human race many, many years to unlearn, and to recover from the effects of the superstitious cult of the shaman, who exists, not only among savages, but also in the most highly civilized races of the world! Superstition is the antithesis of knowledge; in fact, it is but another name for ignorance.

There is yet another exceedingly interesting psychical trait to be noticed in the lower animals, especially in insects; I refer to the instinctive habit, letisimulation (letum, death, and simulare, to feign). The word "instinctive" must not be used, however, when this stratagem is to be observed in the higher animals other than the opossum; for many of these animals sometimes make an occasional and a rational use of it, as I will endeavor to show in the next chapter.



CHAPTER IX

LETISIMULATION

The feigning of death by certain animals for the purpose of deceiving their enemies, and thus securing immunity, is one of the greatest of the many evidences of intelligent action on their part.[108] Letisimulation (from letum, death, and simulare, to feign) is not confined to any particular family, order, or species of animals, but exists in many, from the very lowest to the highest. The habit of feigning death has introduced a figure of speech in the English language, and has done much to magnify and perpetuate the fame of the only marsupial found outside of Australasia and the Malayan Archipelago. "Playing 'possum" is now a synonym for certain kinds of deception. Man himself has known this to be an efficacious stratagem on many occasions. I have only to recall the numerous instances related by hunters who have feigned death, and have then been abandoned by the animals attacking them. I have seen this habit in some of the lowest animals known to science. Some time ago, while examining the inhabitants of a drop of pond water under a high-power lens, I noticed several rhizopods busily feeding on the minute buds of an alga. These rhizopods suddenly drew in their hair-like cilia and sank to the bottom, to all appearances dead. I soon discovered the cause in the presence of a water-louse, an animal which feeds on these animalcules. It likewise sank to the bottom, and, after examining the rhizopods, swam away, evidently regarding them as dead and unfit for food. The rhizopods remained quiet for several seconds, and then swam to the alga and resumed feeding. This was not an accidental occurrence, for several times since I have been fortunate enough to witness the same wonderful performance. There were other minute animals swimming in the drop of water, but the rhizopods fed on unconcernedly until the shark of this microscopic sea appeared. They then recognized their danger at once, and used the only means in their power to escape. Through the agency of what sense did these little creatures discover the approach of their enemies? Is it possible that they and other like microscopic animals have eyes and ears so exceedingly small that lenses of the very highest power cannot make them visible? Or are they possessors of senses utterly unknown to and incapable of being appreciated by man? Science can neither affirm nor deny either of these suppositions. The fact alone remains that, through some sense, they discovered the presence of the enemy, and feigned death in order to escape.

[108] Instinct does not preclude intelligent ideation. In the lower animals death-feigning is undoubtedly instinctive; yet the recognition of danger, which sets in motion the phenomena of letisimulation, is undoubtedly due, primarily, to intelligent ideation in a vast majority of animals. Otherwise this earth would be a lifeless waste.—W.

There is a small fresh-water annelid which practises letisimulation when approached by the giant water-beetle.[109] This annelid, when swimming, is a slender, graceful little creature, about one-eighth of an inch long, and as thick as a human hair; but when a water-beetle draws near, it stops swimming, relaxes its body, and hangs in the water like a bit of cotton thread. It has a twofold object in this: in the first place, it hopes that its enemy will think it a piece of wood fibre, bleached alga, or other non-edible substance; in the second place, if the beetle be not deceived, it will nevertheless consider it dead and unfit for food. I do not mean to say that this process of ratiocination really occurs in the annelid; its intelligence goes no farther, probably, than conscious determination. In the beetle, however, conscious determination is merged into intelligent ideation, for its actions in the premises are self-elective and selective.

[109] Dyticus marginalis. Vide Furneaux, Life in Ponds and Streams, p. 325; foot-note for orthography.—W.

Letisimulation in this animal is by no means infrequent, for I have seen it feign death repeatedly. Any one may observe this stratagem if he be provided with a glass of clear water, a dyticus, and several of these little worms. The annelid is able to distinguish the beetle when it is several inches distant, and the change from an animated worm to a seemingly lifeless thread is startling in its exceeding rapidity.

Even an anemone, a creature of very low organization indeed, has acquired this habit. On one occasion, near St. John's, Newfoundland, I noticed a beautiful anemone in a pool of sea-water. I reached down my hand for it, when, presto! it shrivelled and shrunk like a flash into an unsightly green lump, and appeared nothing more than a moss-covered nodule of rock.

Very many grubs make use of this habit when they imagine themselves in danger. For instance, the "fever worm," the larva of one of our common moths,—the Isabella tiger-moth,—is a noted death-feigner, and will "pretend dead" on the slightest provocation. Touch this grub with the toe of your boot, or with the tip of your finger, or with a stick, and it will at once curl up, to all appearances absolutely without life.

A gentleman[110] recently told me that he saw the following example of letisimulation: One day, while sitting in his front yard, he saw a caterpillar crawling on the ground at his feet. The grub crawled too near the edge of a little pit in the sandy loam, and fell over, dragging with it a miniature avalanche of sand. It immediately essayed to climb up the north side of the pit, and had almost reached the top, when the treacherous soil gave way beneath its feet, and it rolled to the bottom. It then tried the west side, and met with a similar mishap. Not discouraged in the least by its failure, it then tried the east side, and reached the very edge, when it accidentally disturbed the equilibrium of a corncob poised upon the margin of the pit, dislodged it, and fell with it to the bottom. The caterpillar evidently thought the cob was an enemy, for it at once rolled itself into a ball and feigned death. It remained quiescent for some time, but finally "came to life," tried the south side with triumphant success, and went on its way rejoicing. This little creature evinced conscious determination and a certain amount of reason; for it never tried the same side of the pit in its endeavors to escape, but always essayed a different side from that where it had encountered failure.

[110] Mr. George Mattingly, Owensboro, Kentucky.

Many free-swimming rotifers practise letisimulation when disturbed or when threatened by what they consider impending danger. If a "pitcher rotifer" (Brachionus urceolaris) be approached with a needle point, it will cease all motion and sink; the same is true of the "skeleton rotifer" (Dinocharis pocillum) and numerous others of this large family. Again, if a bit of alga on which there is a colony of "bell animalcules" (Vorticellae) be placed in a live box and then be examined with a moderate power, they can be seen to feign death. The rapidly vibrating cilia which surround the margin of the "bells" give rise to currents in the water which can be easily made out as they sweep floating particles toward the creatures' mouths and stomachs. If the table on which the microscope rests be rapped with the knuckles, the colony will disappear as if by magic. Now, what has become of it? If the microscope be readjusted, a group of tubercles will be observed on the alga; these are the vorticellae. They have simply coiled themselves upon their slender stems, have drawn in their cilia, and are feigning death. In a few seconds one, and then another, will erect its stem; finally, the entire colony will "come to life" and resume feeding until they are again frightened, when they will at once resort to letisimulation.

Death-feigners are found in four divisions of animal life; viz., among insects, birds, mammals, and reptiles. Indeed, the most gifted letisimulants in the entire animal kingdom are to be observed in the great snake family. The so-called "black viper" of the middle United States is the most accomplished death-feigner that I have ever seen; its make-believe death struggles, in which it writhes and twists in seeming agony and finally turns upon its back and assumes rigor mortis, cannot be surpassed by any actor "on the boards" in point of pantomimic excellence.

I do not know of any fish which has acquired this strategic habit, but the evidence is not all in, and some day, perhaps, death-feigners may be found even among fishes.[111]

[111] Letisimulation, apparently, is not confined to animals; we see that certain plants have acquired a habit that is strikingly like death-feigning. We are apt to regard the plants as being non-sentient, yet there is an abundance of evidence in favor of the doctrine that vegetable life is, to a certain extent, percipient. Darwin has shown conclusively that plant life is as subject to the great law of evolution as animal life; he has also demonstrated, in his observations of insectivorous plants—the sun-dew (Drosera rotundifolia) especially—that these plants recognize at once the presence of foreign bodies when they are brought in contact with their sensitive glands;[A] he has likewise shown that plants, in the phenomenon known as circumnutation, evince a percipient sensitiveness that is as delicate as it is remarkable.[B] Hence, we need not feel surprised when we find, even in a plant, evidences of such a widespread stratagem as letisimulation. The champion death-feigner of the vegetable kingdom is a South American plant, Mimosa pudica. In the United States, where in some localities it has been naturalized, this plant is known as the "sensitive plant." A wild variety, Mimosa strigilosa, is native to some of the Southern States, but is by no means as sensitive as its South American congener. The last-mentioned plant is truly a vegetable wonder. At one moment a bed of soft and vivid green, the next a touch from a finger and, in the twinkling of an eye, it has changed into an unsightly tangle of seemingly dead and withered stems. In this case death-feigning seems absolutely successful as far as protection is concerned; for surely no grass-eating animal would touch this withered stuff, especially if there were other greens in the neighborhood. Death-feigning in plants, and kindred phenomena, are not due, however, to conscious determination; they are, in all probability, simply the result of reflex action.

[A] Darwin, Insectivorous Plants, Chap. V. et seq.

[B] Darwin, Power of Movement in Plants, pp. 107-109.

Recently, I saw this stratagem perpetrated by a creature so low in the scale of animal life, and living amid surroundings so free from ordinary dangers, that, at first, I was loath to credit the evidence of my own perceptive powers; and it was only after long-continued observation that I was finally convinced that it was really an instance of letisimulation.

The animal in question was the itch mite (Sarcoptes hominis), which is frequently met with by physicians in practice, but which is rarely seen, although it is very often felt, by mankind, especially by those unfortunates who are forced by circumstances to dwell amid squalid and filthy surroundings. Sarcoptes hominis is eminently a creature of filth, and is primarily a scavenger living on the dead and cast-off products of the skin. It is only when the desire for perpetuating its race seizes it that it burrows into the skin, thereby producing the intolerable itching which has given to it its very appropriate name. It is only the females that make tunnels in the skin; the males move freely over the surface of the epidermis. The females make tunnels or cuniculi in the cuticle, in which they lay their eggs, and they can readily be removed from these burrows with a needle. While observing one of these minute acarii through a pocket lens, as it crawled slowly on the surface of the skin, I wished to examine the under surface of its body. When I touched it with the point of a needle in attempting to turn it upon its back, it at once ceased to crawl and drew in its short, turtle-like legs toward its sides. It remained absolutely without motion for several seconds, and then slowly resumed its march. Again I touched it, and again it came to a halt, and took up its onward march only after several seconds had elapsed. Again and again I performed this experiment with like results; finally, the little traveller became thoroughly chilled, and, after a fruitless endeavor to again penetrate the skin, ceased all motion and died.

Many of the coleoptera are good letisimulants. The common tumble-bug (Canthon laevis), which may be seen any day in August rolling its ball of manure, in which are its eggs, to some suitable place of interment, is a remarkable death-feigner. Touch it, and at once it falls over, apparently dead. It draws in its legs, which become stiff and rigid; even its antennae are motionless. You may pick it up and examine it closely; it will not give the slightest sign of life. Place it on the ground and retire a little from it, and, in a few moments, you will see it erect one of its antennae and then the other. Its ears are in its antennae, and it is listening for dangerous sounds. Move your foot or stamp upon the ground, and back they go, and the beetle again becomes seemingly moribund.

This you may do several times, but the little animal, soon discovering that the sounds you make are not indicative of peril to it, scrambles to its feet and resumes the rolling of its precious ball. The habit of making use of this subterfuge is undoubtedly instinctive in this creature; but the line of action governing the use of the stratagem is evidently suggested by intelligent, correlated ideation.

Some animals feign death after exhausting all other means of defence. The stink-bug (pentatomid) or bombardier bug (not the "bombardier beetle") has, on the sides of its abdomen near its middle coxae ("hip bone"), certain bladder-like glands which secrete an acrid, foul-smelling fluid;[112] it has the power of ejecting this fluid at will.

[112] Comstock, The Study of Insects, p. 145.

When approached by an enemy, the stink-bug presents one side to the foe, crouching down on the opposite side, thus elevating its battery, and waits until its molester is within range; it then fires its broadside at the enemy. If the foe is not vanquished (as it commonly is), but still continues the attack, the bombardier turns and fires another broadside from the opposite side. If this second discharge does not prove efficacious (and I have rarely known it to fail), the little insect topples over, draws in its legs, and pretends to be dead.

Many a man has acted in like manner. He has fought as long as he could; then, seeing the odds against him, he has feigned death, hoping that his antagonist would abandon him and cease his onslaughts. The stink-bug in this seems to be governed and directed by reason, though the means used for defence must come under the head of instinct. Many a blind, instinctive impulse in the lower animals is, in all probability, aided and abetted by intelligent ratiocination when once it has made its appearance.

I have seen ants execute a like stratagem when overcome either by numbers or by stronger ants. They curl up their legs, draw down their antennae, and drop to the ground. They will allow themselves to be pulled about by their foes without the slightest resistance, showing no signs of life whatever. The enemy soon leaves them, whereupon the cunning little creatures take to their feet and hurry away.

The most noted and best known letisimulant among mammals is the opossum. I have seen this animal look as if dead for hours at a time. It can be thrown down any way, and its body and limbs will remain in the position assigned to them by gravity. It presents a perfect picture of death. The hare will act in the same way on occasions. The cat has been seen to feign death for the purpose of enticing its prey within grasping distance of its paws. In the mountains of East Tennessee (Chilhowee) I once saw a hound which would "play dead" when attacked by a more powerful dog than itself. It would fall upon its back, close its eyes, open its mouth, and loll out its tongue. Its antagonist would appear nonplussed at such strange conduct, and would soon leave it alone. Its master[113] declared that it had not been taught the trick by man, but that the habit was inherited or learned from its mother, which practised the same deception when hard pushed.[114]

[113] Mr. George Griffiths, Griffiths' Cove, Chilhowee, Blount County, Tennessee.

[114] In the case of the cat and dog the use of this stratagem is not instinctive; it is the rational use of means to obtain a certain desired end. The fact that the dog "inherited the act" from its mother is not a proof of inherited instinct. Instincts are not formed in a single generation.—W.

Most animals are slain for food by other animals. There is a continual struggle for existence. The carnivora and insectivora, with certain exceptions, prefer freshly killed food. They will not touch tainted meat when they can procure the recently killed, blood-filled bodies of their prey. The exigencies of their surroundings in their struggle for existence, however, often compel them to eat carrion.

Dogs will occasionally eat carrion, but sparingly, and apparently as a relish, just as we sometimes eat odoriferous and putrid cheeses, and the Turks, assafoetida.

Carnivora and insectivora would much prefer to do their own butchery; hence, when they come upon their prey apparently dead, they will leave it alone and go in search of other quarry, unless they are very hungry.

Tainted flesh is a dangerous substance to go into any stomach, unless it be that of a buzzard. Heredity and environment have made this bird a carrion-eater, hence, like the jackal, the hyena, and the alligator, companion scavengers, it can eat putrid flesh with impunity. Other flesh-eating animals avoid carrion when they can, for long years of experience have taught them that decaying meat contains certain ptomaines which render it very poisonous; hence, they let dead, or seemingly dead, creatures severely alone. Again, these creatures can see no object in mutilating an animal which, in their opinion, is already dead.

In this discussion of the means and methods of protection that are to be observed in the lower animals, I have brought forward only those in which mind-element was to be discerned. Mimicry and kindred phenomena hardly have a place in this treatise, for they are, undoubtedly, governed and directed by unconscious mind, a psychical phase which, as I intimated in the introductory chapter of this book, would be discussed only incidentally.



CONCLUSION

Judging wholly from the evidence, I think that it can be safely asserted and successfully maintained that mind in the lower animals is the same in kind as that of man; that, though instinct undoubtedly controls and directs many of the psychical and physical manifestations which are to be observed in the lower animals, intelligent ratiocination also performs an important role in the drama of their lives.[115]

[115] Kirby and Spence, Entomology, p. 591.

The wielders of the instinct club bitterly deny that any of the lower animals ever show an intelligent appreciation of new surroundings, that they ever evince intelligent ratiocination. They close their eyes even to the data collected by the chiefs of their tribe, Agassiz, Kirby, Spence, et al., and go on their way shouting hosannas to omniscient, all-powerful Instinct! When one of the lower animals evinces unusual intelligence, or gives unmistakable evidences of reason, they account for it by saying that "it is only instinct highly specialized, or, at least, a so-called 'intelligent' accident."

So far from being "intelligent accidents" are the ratiocinative acts of some of the lower animals (that is, lower than man), that I think that it can be demonstrated analogically that some of these acts are incited by one of the highest qualities of the mind—abstraction.

I do not mean that abstraction which renders the civilized human being so immeasurably superior to all other animals, but rather that primal, fundamental abstraction from which the highly specialized function of man has been developed. The faculty of computing in animals is one evidence of the presence of this psychical trait in its crude and undeveloped state. The quality of abstraction in such ideation is not very high, it is true, yet it is abstraction, nevertheless.

Man possesses two kinds of consciousness—an active, vigilant, cooerdinating consciousness (the seat of which is, probably, in the cortical portion of the brain) and the passive, pseudo-dormant, and, to a certain extent, incoherent and non-cooerdinating consciousness (the so-called sub-liminal consciousness) whose seat is in the great ganglia at the base of the brain (optic thalami and corpora striata), and in other ganglia situated in the spinal cord and elsewhere in the body. My fox terrier has a brain which, in all essential details, does not differ from that of man, and my observations teach me that his mind is the same in kind as that of man as far as memory, emotions, and reason are concerned; then why deny him the possession of abstraction in some degree? I do not mean that abstraction which enables a man to soar into realms of thought infinitely above any effort of ideation to be attained by any of the lower animals, but abstraction in its embryonic state. I am convinced, by actual experimentation, that this dog falls into "brown studies" just as man does; may he not then claim one kind of abstraction, if not another?

The elephant, unquestionably, is able to formulate abstract ideas, the quality of which is very high, indeed. Jenkins wrote to Romanes as follows:—

"What I particularly wish to observe is that there are good reasons for supposing that elephants possess abstract ideas; for instance, I think it is impossible to doubt that they acquire through their own experience notions of hardness and weight, and the grounds on which I am led to think this are as follows:—

"A captured elephant after he has been taught his ordinary duty, say about three months after he has been taken, is taught to pick up things from the ground and give them to his mahout sitting on his shoulders. Now the first few months it is dangerous to require him to pick up anything but soft articles, such as clothes, because things are often handed up with considerable force.

"After a time, longer with some elephants than others, they appear to take in a knowledge of the nature of the things they are required to lift, and the bundle of clothes will be thrown up sharply as before, but heavy things, such as a crowbar or a piece of iron chain, will be handed up in a gentle manner; a sharp knife will be picked up by its handle and placed on the elephant's head, so that the mahout may take it by the handle. I have purposely given elephants things to lift which they could never have seen before, and they were all handled in such a manner as to convince me that they recognized such qualities as hardness, sharpness, and weight."[116]

[116] Romanes, Animal Intelligence, pp. 101, 102; see also Kemp, Indications of Instinct, pp. 120, 130.

Mr. Conklin, the celebrated elephant trainer, once told me that his elephants not only recognized such qualities as weight, sharpness, and hardness, but also volume or dimension.

The kinship of mind in man and the lower animals is indicated also by the phenomenon of dreaming which is to be observed in both. When the active consciousness is stilled by slumber, subconsciousness or ganglionic consciousness remains awake, and sometimes makes itself evident in dreams. I have repeatedly observed my terrier when under dream influence, and have been able to predicate the substance of his dreams from his actions. Like man, the dog is sometimes unable to differentiate between his waking and dreaming thoughts; he confounds the one with the other, and follows out in his waking state the ideas suggested by his dreams.

This, with normal man, is always a momentary delusion; with the dog, however, it may last for some little time. Thus, I have seen my dog chase imaginary rats around my room after having been aroused while in the midst of a dream. His chagrin when he "came to himself" and saw me laughing was always strikingly apparent.

The brains of the lower animals are susceptible to the action of drugs, whose effects on them are identical with the effects noticed when the human brain is under drug influence. Alcohol, chloroform, ether, opium, strychnine, arsenic, all produce characteristic symptoms when they are introduced into the circulatory system of the lower animals. Even the very lowest animalcules give this evidence as to the kinship of nerve and ganglionic or brain elements in man and the lower animals.

I have repeatedly noticed the action of alcohol on rhizopods. When small and almost inappreciable doses were exhibited, the little creatures became lively and swam merrily through the water; but, when large doses were given, they soon became stupefied and finally died. I have seen drunken jelly-fish rolling and tacking through the alcohol-impregnated water for all the world like a company of drunkards.[117] They soon became sober, however, when they were placed in fresh water, but remained listless and inert for some time afterward.

[117] Compare Romanes, Jelly-Fish, Star-Fish, and Sea-Urchins, p. 227.

Coleoptera, hymenoptera, diptera, in fact, all insects exhibit the characteristic effects of alcohol when under its influence. Horses, dogs, cats, monkeys—all mammals are affected characteristically by alcohol, and it not infrequently happens that they willingly become drunkards.[118]

[118] Lindsay, Mind in the Lower Animals, pp. 81-93.

Animals also appear to become cognizant of the fact that certain substances are medicaments, and they will voluntarily search for and take such substances when they are ill. Bees are perfectly aware of the astringent qualities of the sap of certain trees, notably the dogwood and wild cherry, and, when afflicted with the diarrhoea, can be seen biting into, and sucking, the sap from the tender twigs of such trees. Dogs, when constipated, will search for and devour the long, lanceolate blades of couch-grass (Triticum repens); horses and mules, when they have "scours," eat clay; cattle with the "scratches" have been seen to plaster hoof and joint with mud, and then stand still until the healing coating dried out and became firm; and elephants have been known, time and again, to plug up shot holes in their bodies with moistened earth.[119]

[119] Romanes, Skinner, Sir R. Tennent, Bingley, Forbes, et al.

Again, the recognition of the rights of property cannot be attributed to instinct, neither can it fall under the head of "intelligent accidents," yet many animals lower than man recognize, to a certain extent, the rights of property. For instance, in 1879, two very intelligent chimpanzees were on exhibition at Central Park. One of these animals claimed as her property a particular blanket, and, notwithstanding the fact that there were other blankets in the cage in which they were confined, always covered herself with this blanket. She would take it away from her companion whenever she wished to use it. Again, two turkeys on my place deposited their eggs in the same nest. The hen which first built and used the nest regarded the spot as her individual home; therefore, whenever she found the other hen's egg in the nest, she would break it with her beak, and then carry it some distance away. This I have seen her do repeatedly.

Many dogs, cats, and other animals regard certain rugs, cushions, etc., as their own property, and resent any interference with them. It seems to me that in all such instances these animals regard themselves as individuals; that they recognize the psychical as well as the physical difference between the Ego and the Tu as soon as they begin to recognize the rights of property.

Those who hold that instinct governs all actions of the lower animals, usually claim that man is the only tool-user. This is a gross mistake—elephants, when walking along the road, will break branches from the trees and use them as fly-brushes;[120] these creatures also manufacture surgical instruments, and use them in getting rid of certain parasites;[121] monkeys use rocks and hammers to crack nuts too hard for their teeth; these creatures also make use of missiles to hurl at their foes;[122] chimpanzees make drums out of pieces of dry and resonant wood;[123] the orang-utan breaks branches and fruit from the trees and hurls them at its foes;[124] the gorilla and chimpanzee use cudgels or clubs as weapons of offence or defence;[125] monkeys make use of sticks in order to draw objects within their reach;[126] spiders suspend pebbles from their webs in order to preserve stability,[127] etc.

[120] Peal, Nature, Vol. XXI. p. 34; quoted also by Romanes.

[121] Peal, Nature, Vol. XXI.

[122] Romanes, Animal Intelligence, p. 485 et seq.

[123] Lindsay, Mind in the Lower Animals, Vol. I. p. 410.

[124] Wallace, Malayan Archipelago, p. 41.

[125] Lindsay, loc. cit. ante, p. 413.

[126] Belt, Naturalist in Nicaragua, p. 119.

[127] Buechner, Geistesleben der Thiere, p. 318.

I could prolong this list to a much greater length, but think it hardly necessary. I think that I have demonstrated that man is not the only tool-user.

Even such dyed-in-the-wool creationists as Kirby and Spence are forced to admit the presence of reason in insects.

"Such, then, are the exquisiteness, the number, and the extraordinary development of the instincts of insects. But is instinct the sole guide of their actions? Are they in every case the blind agent of irresistible impulse? These queries, I have already hinted, cannot, in my opinion, be replied to in the affirmative; and I now proceed to show that though instinct is the chief guide to insects, they are endowed also with no inconsiderable portion of reason."[128]

[128] Kirby and Spence, Entomology, p. 591.

Studied both objectively and subjectively, insects present indisputable evidence of reason. Not the higher abstract reason of the human being, however, but reason in its primal, fundamental state.

The difference between instinct and reason is not generally understood, and, as I believe that most readers can comprehend an illustration much quicker than an explanation, I will use the former in order to bring out this difference.

The hen which sits three weeks on a china egg is influenced by blind impulse—instinct; while the turkey which discovers the eggs of her rival in her nest, and destroys them, is directed by something infinitely higher—by reason. The using of a common nest never occurs among these birds in a wild state, neither is it of so frequent occurrence among domesticated turkeys as to have formed an instinctive habit.

Again, the honey-making ants which left their patrol line in order to slay the wounded centipede may have been, and probably were, influenced by instinct; another and wholly different psychical trait, however, impelled them to fill up the trench dug with my hunting knife. This accident could not have occurred, perhaps, to them in a state of nature, or if by any possibility it had ever occurred before, the chances are that such occurrences were few in number, and that they happened at long intervals of time, thus precluding the establishment of an instinctive habit. Nor do I think it possible for this action to come under the head of "specialized instinct," for the same reason. By the very nature of things there can be no such thing as an "intelligent accident"; the term is itself a contradiction, therefore the performance of these ants must be considered an act of intelligent ratiocination.

In this discussion of mind in the lower animals I have endeavored to show that the psychical traits evinced by them indicate that their mental organisms, taken as a whole, are the same in kind as that of man.

* * * * *



BIBLIOGRAPHY

Bates. The Naturalist on the River Amazon.

Belt. The Naturalist in Nicaragua.

Buechner. Geistesleben der Thiere.

Carter. Annals of Natural History.

Clark. Mind in Nature.

Comstock. The Study of Insects.

Darwin. The Descent of Man; The Origin of Species; Insectivorous Plants; Formation of Vegetable Mould; The Expression of the Emotions; Power of Movement in Plants.

Dewar. Physiological Action of Light, Nature, 1877.

Figuier. Reptiles and Birds.

Furneaux. Life in Streams and Ponds.

Gibson. Sharp Eyes.

Haeckel. History of Creation; Evolution of Man.

Hartman. Anthropoid Apes.

Hickson. The Fauna of the Deep Sea.

Huber. The Natural History of Ants.

Huxley. The Study of Zooelogy.

Kemp. Indication of Instinct.

Kirby and Spence. Entomology.

Lindsay. Mind in the Lower Animals in Health; Mind in the Lower Animals in Disease.

Lubbock. Origin and Metamorphoses of Insects; Ants, Bees, and Wasps; The Social Hymenoptera; The Senses, Instincts, and Intelligence of Animals.

Luys. The Brain and its Functions.

Mantagazza. Physiognomy and Expression.

Maudsley. The Physiology of Mind; Body and Will.

Miller. Four Handed Folk.

Peschel. The Races of Man.

Pettigrew. Animal Locomotion.

Peal. Nature, Vol. XXI.

Quatrefages. The Human Species.

Reclain. Body and Mind.

Romanes. Animal Intelligence; Mental Evolution in Animals; Mental Evolution in Man; The Jelly-Fish, Star-Fish, and Sea-Urchin.

Roscoe. Life of Leo the Tenth.

Schmidt. The Mammalia.

Schneider. Thierische Wille.

Semper. Animal Life.

Tuke. Influence of the Mind upon the Body.

Van Beneden. Animal Parasites and Messmates.

Wallace. Island Life; The Malay Archipelago.

Whitney. Life and Growth of Language.

White. A Londoner's Walk to Edinburgh.

Yarrell. British Fishes.

* * * * *



INDEX

A

ACINETA MYSTACINA, amoeba catches and devours an, 50.

ACTINOPHRYS, power of differentiation in A. Eichornii, 7; Brachionus captured by, 7; uric acid crystals and sand grains in an experiment with, 9; taste in, 9; sight in, 11; memory of locality in, 49, 52; lying in wait for, and devouring the young of, a pythium, 49; love of pastime in, 123; death-feigning by, 201; effect of alcohol on, 219.

ADELOPS, homing sense in blind, 196; author's experiments in demonstrating homing sense of blind, 196.

ALBINISM, axolotl affected by, 182; difference between etiolation and, 182, 184.

ALCIOPE, eyes of, 17.

ALGA, stentor feeding on spores of, 47.

AMOEBA, young acineta caught by, 51.

ANEMONE, Romanes' experiment with, 42; death-feigning by, 205.

ANERGATES, parasitic, 156, 157.

ANGLEWORM, differentiation between light and darkness by, 54; experiments with light on, 55; ocelli of, 55; Darwin's theory as to deafness in, 55; organs of audition in, 56; author's experiments with, 56; conscious choice in, 56; taste in, 56, 57.

ANT, memory of locality in the, 62; memory of friends (kindred) in the, 65; Huber's observations, 66; author's experiments with Lasius niger, 66; claviger beetles recognized and petted by, 73; gray matter in the brain of, 99; nerve-cells and nerve-filaments in the brain cortex of, 99; Lubbock's experiments (chloroform and alcohol) with, 99; sympathy evinced by, 100; parental care of worker ants for young, 103; love of amusement in the, 125; author's observations of L. flavus, 125, 126; Claviger foveolatus fondled by, 126; Huber's observations of pratensis, 125; Lubbock's observations of Beckia, a pet of, 126; author's observations of Podura in the nests of F. fusca and F. rufescens, 126; evidence of reason in the, 152; funeral of an, 153; battle between, 153; author's verification of Huber's experiment with slave, 155; degeneration in, 155; Lubbock's summary of degeneration in, 156; homing sense in the, 197; death-feigning in the, 212.

ANTHROBIA, eyeless, 11.

APE, cat affectionately treated by an, 83.

APHIS, ants domesticate the, 73.

ARGIOPE, mason wasps for food prefer the spider, 170.

ATROPIA, sympathetic nerves paralyzed by, 191.

AXOLOTL, color-changing in, 184; Paul Bert's experiments with, 184; Semper's experiments with, 184; Koelliker's experiments with, 184.

B

BALANCERS, of Tabanus atratus, 34; of Chrysops niger, 33; of Diplosis resinicola, 33.

BASCANION CONSTRICTOR, recognition of individuals by, 75; bird decorates its nest with skin of, 127.

BASS, parental affection in, 138; homing sense in black, 200.

BECKIA, ants domesticate and pet, 126.

BIRD, memory of individuals in, 76, 77; gratitude in, 77, 93; homing sense in, 199.

BOMBARDIER BUG, death-feigning in, 211.

BRACHIONUS, actinophrys captures, 7.

BRACHIONUS URCEOLARIS, death-feigning in, 206.

BUMBLEBEE, revenge and anger in, 71; recognition of a certain dog by, 71.

BURYING BEETLE, homing sense in, 197.

BUTTERFLY, suitable food for larva selected by, 103; age of tropical, 137; Miranda's observations, 137, 138.

C

CALOTIS, third eye of, 27.

CANTHON LAEVIS, death-feigning in, 210.

CAPUCHIN MONKEY, surgical operation on a, 95; faith in man's ability to aid evinced by a, 96.

CARABIDAE, auditory vesicles of, 37; memory of locality in, 64.

CAT, pride of offspring in a male, 142; idea of time shown by a, 177.

CATFISH, parental affection in, 138, 139.

CERAMBYX, sense of hearing in, 36; Will's experiment with, 36.

CHACMA, cat chosen as friend by, 83; author's test for memory of individuals in, 84.

CHAMELEON, educated, 75; recognition of individual by, 75.

CHICK, pigment cells in embryonic, 186, 187.

CHIMPANZEE, laughter and smiles evinced by, 89; faculty of computing in, 177; recognition of property rights by, 221.

CHRYSOPS NIGER, balancers of, 33; organs of hearing in, 33.

CICINDELIDAE, auditory vesicles of, 37; memory of locality in, 64.

CLAVIGER FOVEOLATUS, ants make a pet of, 73.

COCCINELLAE, peculiar assemblages of female, 126, 127.

COCK, friendship between a drake and a, 78; fondness for violin music in a, 122.

CONSCIOUSNESS, definition of, 43; time element in, 44; the probable location of active, 216; the probable location of the sub-liminal, 216.

CORYDALIS, auditory rods of, 30.

COW, dog the guardian and friend of a, 80.

CRAB, Pouchet's experiment on the chromatophores of, 189.

CRAYFISH, eyes of, 21; power of vision in, 23; pugnacity of, 23.

CRICKET, ears of, 31.

CYMOTHOE, eyes of fresh-water, 13.

D

DETERMINATION, the origin of conscious, 40.

DINOCHARIS POCILLUM, death-feigning in, 206.

DIPLOSIS RESINICOLA, balancers of, 33.

DIPTERA, ears of, 33; love of pastime in, 125.

DOG, cow chosen as a friend by a, 78; laughter in, 90; fondness for certain musical keys in the, 112; author's experiments with the, 113; origin of musical discrimination in the, 114; knowledge of the echo in the, 115; author's observations of an echo-loving, 115; parental affection in the, 141; abstract idea of numbers in the, 173, 174; phenomenon of dreaming in the, 218; medication by sick, 220.

DROSERA ROTUNDIFOLIA, insectivorous, 208.

DUCK, friendship between bantam cock and, 78; hawk attacked and killed by, 78; sense of direction in, 199.

DYTICUS MARGINALIS, auditory rods of, 30; death-feigning in a fresh-water annelid when approached by, 204.

E

EAGLE, recognition of individuals by, 76.

EAR, Dyticus, 30; corydalis, 30; grasshopper's, 31; Tabanus, 34.

EARWIG, method of incubation practised by, 105; care of young by, 105; M. Geer's experiment with, 105; love of offspring in, 106; author's experiments in testing parental affection in the, 136.

ECITON HAMATA, ants of the same species rescue an imprisoned, 100; Belt's experiments in testing the sympathy of, 101.

ELEPHANT, abstract ideation in the, 217; Conklin's testimony as to abstract ideation in, 218; mud used to stop bullet holes by, 220; a branch of a bush used as a fan by, 221.

EPIPONE SPINIPES, method of supplying larva with fresh food used by, 104; differentiation in the amount of food for male and female grub, 104.

ETIOLATION, definition of, 184, 185.

EUPLOCINAE, length of life in tropical, 137.

EYE, flounder's, 9; plaice's, 9; sole's, 9; mole's, 10; fresh-water Cymothoe's, 13; OEquorea's, 15; sea-urchin's, 16; oyster's, 17; Alciope's, 17; snail's, 19; crayfish's, 21; Gyrinus', 23; Periophthalmus', 25; Onchidium's, 26; calotis', 27.

F

FISH, phosphorescent and pigmented, 13; parental affection in, 138; sense of direction in, 200.

FLEA, memory in the, 86; dancing and military evolutions by, 86; method of educating the, 87.

FLOUNDER, the origin of unilateral eyes in, 9.

FORMICA FUSCA, sympathy in, 100; species of Podura domesticated by, 126.

FORMICA RUFA, sympathy evinced by, 102.

FORMICA RUFESCENS, pet beetles in the nest of, 126.

FORMICA SANGUINEA, slave-making habit in, 155; sympathy evinced by, 102; Lubbock's observations of a sick, 102.

FROG, tinctumutation in the, 182; chromatophores of, 182; Heincke's observations, 183; location of color-changing sense in, 190.

G

GADFLY, selection of suitable spot for oviposition by, 103.

GILT CATFISH, gyropeltes make the toilet of, 130; color-changing in, 183; author's experiments on the color-changing function of, 191.

GOBIUS RUTHENSPARRI, tinctumutation in, 183.

GOGGLE-EYE PERCH, love of offspring in, 138; homing sense in, 200.

GOOSE, homing sense in the, 199.

GORILLA, use of cudgel by, 222.

GRASSHOPPER, ears of, 30.

GYRINUS, indifference to seasons shown by, 23; eyes of, 24.

GYROPELTES, health of gilt catfish dependent on, 130.

H

HELICONIDAE, length of life in, 138.

HELIX POMATIA, love of amusement in, 123; author's observations, 124.

HEMIPTERA, organs of audition in, 29.

HOG, friendship between a dog and a, 81.

HONEY BEE, recognition of impending calamity by, 90; consternation and dismay manifested by, 90; remarkable engineering feat by, 91; joy evinced by, 91; grief shown by, 91, 92; Huber's experiment demonstrating reason in, 178.

HORSE, love of offspring in the, 143; seeking man's aid when in trouble, 144; self-medication by, 220.

HOUND, death-feigning by, 212.

HUMMING-BIRD, decorative instinct in, 128.

HYDRA, water-louse feeding on the buds of, 52.

HYDROZOA, nerve-tissue in, 41.

HYMENOPTERA, recognition of kindred in social, 69.

I

ICHNEUMON, method of ovipositing in the bodies of caterpillars used by, 104.

INSTINCT, definition of, 147, 148.

J

JAY, parental love in the, 142; battle between cat and, 143.

JELLY-FISH, anatomy, physiology, and psychology of, 4; nerve-ring in nectocalyx of, 5; "eyes" of, 5; manubrium or "handle" of, 5; sensitiveness of nervous system in, 5; pulsing of nectocalyx in, 5; intoxicated, 15; light sought by, 15; effect of the excision of the marginal bodies of, 52; conscious determination in, 52; effect of alcohol on, 219.

K

KATYDID, color-changing function in, 191, 192.

L

LAND TERRAPIN, memory of locality in, 65; homing sense in, 65; author's experiments with, 65.

LASIUS FLAVUS, author's experiments with, 67; slow in recognizing kin, 67; ants of the same species disinter buried, 101.

LASIUS NIGER, memory of kindred in, 66.

LEPIDOPTERA, organs of hearing in, 35.

LETISIMULATION, definition of, 202; origin of, 206.

LIMPET, homing sense in, 194; Romanes on the homing sense in, 195.

LIOTHE, fowls cleaned by, 129.

LIZARD, Ada Sterling's account of Kate Field's music-loving, 119; fondness for music in the tree, 119; Chilhowie "singing," 120; author's experiment with the piccolo on, 120.

LOBSTER, love of offspring in the, 137; battle between monkey and gravid, 137.

LOCUST, love of cleanliness in, 130; diamond mistaken for dewdrop by, 131; carnivorous tastes in the, 131; description of the toilet of a, 132.

LYCOSA, love of music in, 108; tameness of, 110.

M

MAMMOTH CAVE, eyeless spider of, 11; eyeless fish of, 11; homing sense in the beetles of, 196.

MANDRIL, a revengeful, 95.

MEDUSA, intoxicated, 15.

MELANOPLUS, reenforcing auditory ganglia of, 32.

MEMORY, its discussion under four heads, 60.

MIMOSA PUDICA, death-feigning by, 208.

MIMOSA STRIGILOSA, death-feigning by, 208.

MIND, definition of, 1.

MOLE, degeneration of sight organs in, 10.

MONERON, non-differentiation of nerve-cells in, 3; nervoid elements in, 3.

MONKEY, author chosen as a friend by, 82; a laughing, 89; sorrow and reproach manifested by, 97; faculty of computing in the, 177; use of hammer by a, 222.

MORPHOLOGY, its correlation with physiology, 2.

MOUSE, love of music in, 116; musical discrimination in, 117; Quigley's observations, 117; Benedick's experiments with, 117; author's observations and analysis of the song of "singing," 118; Ada Sterling's observations of music-loving, 118, 119.

MULE, idea of time evinced by a, 175, 176.

MYRIANIDA, eyes of, 17; reproduction in, 18.

MYRMECA RUGINODIS, memory of friends (kindred) in, 68; experiments with, 68.

MYRMECOCYSTUS, the honey-making, 157; natural history of, 158; author's experiments in testing the reasoning powers of, 158, 159; division of labor in a colony of, 161.

N

NECTOCALYX, marginal bodies in jelly-fish's, 51.

NERVE, transmission of impressions through, 41; the power of discrimination in, 41; the association of ideas (impressions) in, 43; memory in, 43.

NEWT, tinctumutation in, 186; author's experiments with, 186.

O

OEQUOREA, eyes of, 15.

OESTRUS EQUI, selection of foreleg of horse for oviposition by, 103.

ONCHIDIUM, cephalic eyes of, 26; dorsal eyes of, 26.

OPOSSUM, letisimulation in the, 202, 212.

ORANG-UTAN, laughter in the, 89; use of missiles by, 222.

OX, homing sense in the, 199, 200.

OYSTER, eyes of, 16.

P

PAPILIONINAE, length of life in tropical, 137.

PERCH, love of offspring in the white, 138.

PERIOPHTHALMUS, habitat of, 25; peculiar mode of life of, 25; eyes of, 25; food of, 26.

PIGEON, love of music in the, 122; Lockman's account of a music-loving, 122; musical discrimination in, 122.

PIPE-FISH, parental affection in the, 139; Risso's observations, 139.

PLAICE, the origin of unilateral eyes in the, 9; absence of color-changing faculty in blind, 188; Pouchet's demonstration of the color-changing function of the sympathetic nerves in, 189.

PODURA, F. fusca and F. rufescens make pets of, 126; author's observations of, 126.

POLYERGUS, lowering tendency of slavery shown by, 155, 156.

PRIONUS, author's experiments in locating organs of hearing in, 36.

Q

QUAIL, domesticated, 111; love of caresses in, 111; love of instrumental music in, 111; fondness for the singing voice in, 112.

R

RAT, fondness for instrumental music in, 116; power of musical discrimination in, 116.

REASON, definition of, 147; difference between instinct and, 148.

RHIZOPOD, sense of direction in, 48; Carter's observations of, 49; memory in, 60.

ROBIN, homing sense in, 199.

S

SAND-WASP, memory of locality in, 62; author's experiments with, 63.

SARCOPTES HOMINIS, death-feigning in, 209.

SATIN BIRD, aestheticism in the male, 128; author's observations of, 128.

SEA-URCHIN, eyes of, 16.

SNAIL, eyes of, 19; visual powers of, 19; courtship of, 20; location of sense of direction in, 194; author's experiments with, 194; author's experiments in demonstrating homing sense in the, 194.

SNAKE, love of young in, 140; author's experiment in testing parental affection of, 140; sense of direction and "homing instinct" in, 198; author's observations of "homing instinct" in, 198.

SOLE, the origin of unilateral eyes in the, 9.

SONG-SPARROW, memory of individuals in, 77; parental affection in, 143.

SPANIEL, a laughing, 89.

SPIDER, memory in, 72; recognition of individuals by, 73; love of music in the, 108; author's experiments with piano on, 108; author's experiments with pipe organ on, 109; Reclain's observations on the love of music in, 109; decorative instinct present in, 110; peculiar web spun by, 110; parental affection in, 135; author's experiment in testing parental love of, 135; use of implement (pebble anchor) by, 222.

SQUIRREL, memory in the, 70.

STENTOR POLYMORPHUS, nervous system of, 46; observations of and experiments with, 47; conscious determination in, 47; ganglia of, 47.

STRONGALOGNATHUS, degeneration caused by the habit of slave-making in, 155, 156, 157.

T

TABANUS ATRATUS, balancers of, 33; loss of equilibrium in, 33; anatomy of balancers of, 34; auditory hairs of, 34.

TERMES, kinds of individuals in a colony of, 161; number of eggs laid by queen of, 162; size of gravid queen, 162; New Mexican, 163; soldiers and workers of, 163; instincts and reasoning powers of, 164.

TERRIER, love of music in, 113; musical discrimination in, 113; abstract ideation in, 216.

TINCTUMUTATION, definition of, 182; location of color-changing sense centre in, 183.

TOAD, memory in the, 87; a performing, 87; parental affection in the Surinam, 140.

TRITICUM REPENS, sick dogs medicate themselves with, 220.

TURKEY, memory of individuals in the, 76; recognition of property rights by the, 221.

V

VANESSA, tinctumutation in the larva of, 192.

VIPER, death-feigning in the, 207.

VOLITION, definition of conscious, 39; physiological aspect of, 40.

W

WASP, memory in the, 62; author's experiments in testing memory in the, 63, 69; memory of kindred in the, 65, 69; memory of locality and of events in the, 85; knowledge derived from a single experience by a, 85; length of life in the mud-dauber, 138; evidence of reason in the mud-dauber, 149, 150; psychic actualities of easy acquirement in the ant, the bee, and the, 151; faculty of computing in the mason, 169; author's experiments in testing the computing faculty in the, 170; method of preparing food for the male and female grubs used by the mason, 170.

WATER-LOUSE, sense of direction in the, 194.

WREN, distress and grief evinced by, 93; recognition of individuals by, 93; gratitude shown by, 94.

* * * * *



ECONOMICS.

BY EDWARD THOMAS DEVINE, Ph.D.,

General Secretary of The Charity Organization Society of the City of New York; Sometime Fellow in the University of Pennsylvania; and Staff Lecturer of the American Society for the Extension of University Teaching.

* * *

16mo. Cloth. $1.00.

* * *

"Long experience in the popular exposition of the principles of political economy has given Dr. Edward Thomas Devine peculiar qualifications for the preparation of a text-book upon this subject, and his recently published 'Economics' is an excellent book of its kind. It may be warmly recommended."—Dial.

"It is a lucid, and entertaining exposition of the subject."—St. Louis Globe-Democrat.

"Every young man and woman on the verge of the real life that comes with gaining their majority should read a good work on this subject, and we could recommend no better than this particular volume."—Iowa State Register.

"Mr. Devine's will undoubtedly be found a handbook suited to its purpose."—Milwaukee Sentinel.

* * *

THE MACMILLAN COMPANY, 66 FIFTH AVENUE, NEW YORK.

* * *



A HISTORY OF PHILOSOPHY

WITH ESPECIAL REFERENCE TO THE FORMATION AND DEVELOPMENT OF ITS PROBLEMS AND CONCEPTIONS.

By DR. W. WINDELBAND, Professor of Philosophy in the University of Strassburg.

Authorized Translation by JAMES H. TUFTS, Ph.D., Associate Professor of Philosophy in the University of Chicago.

8vo. Cloth. $4.00, net.

* * *

"The work commends itself to every student of philosophy."—Boston Transcript.

"As a book of reference it will not supersede Ueberweg's History, but it is more readable and gives a much better view of the connection of philosophic thought from age to age and of the logical relation of the various schools and thinkers to each other. There is no other work available in English which presents these aspects of a subject so well, and both English and American students who do not read German will thank Professor Tufts for giving them the book in their own language."—Critic.

"No preceding history so fully occupies its field and answers its purpose. It should have a place in the library of every student of Philosophy."—Chicago Tribune.

"We believe that this is as nearly perfect a book in the form of a history of philosophy as has ever been produced."—Boston Herald.

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THE MACMILLAN COMPANY, 66 FIFTH AVENUE, NEW YORK.

THE END