The Dawn of Reason; or, Mental Traits in the Lower Animals

of these means are very wonderful indeed. It is not my purpose to discuss instinctive protective habits in this chapter; I wish rather to call attention to

r of these faculties is instinctive, but they are, on the contrary, true senses, just as hearing, or taste, or smell is a sense. Careful dissections and repea

og's foot be placed on the stage of a microscope and examined with an achromatic lens, the chromatophores can readily be made out. Artificial irritation will immediately occasion them to contract, or, as is frequently the case, when contracted, will occasion them to dilate, and the phenomena of tinctumutation may be observed in facto. Under irritation the orange-colored chromatophores, when shrunk, become brown, and the contracted yellow ones, when dilated, become greenish yellow. When all the chromatophores are dilated, a dark color will predominate; when they are contracted, the skin becomes lighter in color. Besides the pigment-cells just described, Heincke discovered another kind of chromatophore, which was filled with iridescent crystals. They were only visible, as spots of metallic lustre, when the cells were in a state of contraction. He observed these latter chromatophores in a fish belonging to Gobius, the classical name of which is Gobius ruthensparri.[94] I have seen this kind of color-cell in the skin of the gilt catfish, which belongs to a family akin to Gobius. The skin of this fish retains its vitality for some time after its removal from the body of the living animal, and the chromatophores will respond to artificial irritation for quite a while. In making my observations, however, I prefer to dissect up the skin and leave it attached to the body of the fish by

ound in animals. The former play one of the most important r?les in the drama of plant life, inasmuch as they subserv

cell bodies secreting pigmentary matter for the purpose of protection. Of course, when animals are subjected to darkness for very long periods of time, the chromatophores are modified, and, sometimes, are who

mmoth Cave, Kentucky, in the neighborhood of Gorin's Dome, which is far within the depths of the cave. As beetles rarely

no heat rays. I believe that heat is a prominent factor in the production of color; the dis

tion,-that is, through several generations. My animals were kept under observation from the extrusion of the eggs until

as dark; while those reared in white ironstone crocks and in diffused daylight were very much lighter, being pearl-gray in color. This a

nd in the cutis of the embryonic chick, about the fifteenth day, certain pigment-cells. These cells have entirely disappeared by the twenty-third da

rfect eyesight were not good tinctumutants, notwithstanding the fact that they had the chromatophoric function. He showed, by his experiments on frogs, that the activity of the chromatophores depended entirely on the healthy condition of the eyes,-that is, so far as the phenomenon of tinctumutation was concerned. So long as the eyes remained intact and connected with the brain by the optic nerve, the light reflected from the surrounding objects exerted a powerful influence on the chromato

state of relaxation; and this specimen was as distinct from its companions as from the bottom of the aquarium. Closer investigation proved that the creature was totally blind,[99] and thus incapable of assuming the color of the objects around it, the eyes being unable to act as a medium of communication between them and the chromatophores of the skin."[100] Thus far Pouchet had only confirmed Liste

receive the message through the cord and spinal nerves. He then divided the sympathetic nerves, and the chromatophores lost at once th

ortance, though he failed to recognize it as such. He was s

ical importance of this discovery. This fact makes the phenomenon of tinctumutation an involuntary act on the part of the animal possessin

to, and have even solved, so I believe and unhesitatingly assert, the puzzling probl

nd 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 pe

t injury to the optic centres), the chromatophoric function ce

he 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

several specimens of gilt catfish. This is a pond fish and is quite abundant throughout the middle United States. It is

en out. They were of a dusky drab color when first taken out, but soon regained their vivid tints when placed in a white vesse

her on the lighter-colored leaves of a locust. She could be easily seen when first placed on the

n. The chromatophores in the larva of Vanessa are very numerous, and this grub is a remarkab

s of defence. In some animals it is developed in a wonderful manner. Wherever it is found it becomes to the animal

t." 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 t

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

ection 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 enti

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 i

ge 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 dis

in); this ganglion lies immediately between and below the "horns" (eye-stalks), and is composed of

nd 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 t

e 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 depre

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 ha

eneath 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 l

d by their sense of direction alone, but as soon as they ar

determined. After feeding, it will invariably return to a certain spot in order to enjoy its nap in peace; for,

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

, 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

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 bro

rier-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

banon, Kentucky; when this gentleman started to return home, his father gave him

0 miles below Louisville, Kentucky, and, in a week or so, were found one morning at the gate of their old home at Lebanon. Dir

hich they will share with no other fish. The black bass, and brook trout, and

iece 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 sa

tors, 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

ious cult of the shaman, who exists, not only among savages, but also in the most highly civilized races

isimulation (letum, death, and simulare, to feign). The word "instinctive" must not be used, however, when this stratagem is to be observed in the higher ani

TNO

ation and the sense of direction or the "homing sense." Heretofore they have be

r, Animal

d., p. 8

e slight amount of color in the animals reared under the yellow light was due to the "optic current" of Dewar. The microscope showed that the chromatophores were just

mper, Animal

mper, Animal

d "angel fish" which shows, most conspicuously, a lack of tinct

per, Animal Li

action renders the sensual nature of

hel, The Races of Man; Lombroso, L'Uomo Delinquente; Ellis, The Criminal;

Intelligenc

in a state of slumber. Their sleep may not be the physiological slu

nfield, Esq., Ow

day-laborer who had been temporarily employed to assist the gardener. An autopsy revealed a

e, Life of