Chapter XII: 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 rôle 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, coördinating 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-coördinating 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] Büchner, _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._

Büchner. _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 Zoölogy._

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;
Kölliker'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 LÆVIS, death-feigning in, 210.

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

CARABIDÆ, 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.

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

CLAVIGER FOVEOLATUS, ants make a pet of, 73.

COCCINELLÆ, 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.

EUPLOCINÆ, 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

HELICONIDÆ, 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, reënforcing 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

PAPILIONINÆ, 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, æstheticism 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._

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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._

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