Abortion: v. Rudimentary Organs.
Aconitum napellus, imported: vari-
ation in, 534.

Acraeida protective elasticity of,
166-7.

Agrionida: protective coloura-
tion of, 173.

ALLEN, GRANT: on colouration of
arctic fauna, 189-90; on survival
of fittest amongst wasps, 272-3.
ALLEN, J. A.: on variations in

birds, 488.
Allium its storage of water, 413.
ALTUM, DR. B.: on sudden great
increases and subsequent pos-
sible great destruction of mice,
53.
Amblystoma: v. Axolotl.
AMERICAN

NATURALIST
(quoted by Darwin): on spike-
horned buck, 361.
Amaba instinct in, 237; propa-
gation by fission, 577; Herbert
Spencer on, 567, 570.
Amphimixis: 370-1.

Ancon Dogs, Jaguar, Ram : ข.
Dogs, Jaguar, Ram.

Animals made for use of man":
124-30.

Antelopes: Survival of Fittest

among, 63; utility of specific
variations in, 418-v. also Deer.
Ant-lion, larva of: instinct in, 234.
Ants instinct and character in,
258; queens and workers pro-
duced from same or different
kind of eggs, 268.
Aphides: potential rate of increase,

46; protective secretion of, 166.
ARGYLL, DUKE OF: on protective
colouration of birds, 185; on in-
stinct in water-ouzel, 221-3; on
special creation, 521.
ARNOLD, MATTHEW: Empedocles
on Etna quoted, 4, 8.

Arrested Development: 543-9.
Artemia: variation in, 536-7.
Artificial Selection: analogy of
Natural Selection to, 130-56.

"Methodical" and "Un-
conscious" (Darwin), 136-7.
Asses, Imported: rapid multiplica-
tion of, 52.

Athleticism, Hereditary: 434-5.
AVELING, DR. EDWARD: on sen-
sitive faculties of sun-dew, 286-7;
on the hypothesis of Natural
Selection, 454.

Axolotl transmutation of, into
Amblystoma, 546-7.

Baboons co-operation amongst,
93.

BAILEY, PROF.: on the influence of
external conditions on squashes,

396.

BAKER, SIR S. W.: on struggle for
existence, 22-3; on indiscriminate
destruction of life in nature, 62;
on parental devotion of cow, 82;
on co-operation amongst birds of
prey, 92.

Balancement, Law of: 335-6.
BALFOUR, F.M.: on the Darwinian
theory, 462-3; on limbs of higher
vertebrata, 503; on sensitiveness
of cells, 573-4, 575.

BALL, J. on geographical distri-
bution, 531.

BALL, W. P.: on the effects of use
and disuse, 432; on law of
economy, 512.
Baptanodon discus: an illustration
of conformity to type, 502, 503,
506.

BARBER, MRS.: on influence of
environment on colouration of
caterpillar, 408.

BASTIAN, DR. H. C.: on animal
instincts, 286.

BATES, H. W.: on animal coloura-
tion, 160; on mimicry in rela-
tion to Natural Selection, 178,
194-5; on protective habits of
shrimps and prawns, 184-5; on
unprotectiveness of nauseous
taste amongst insects, 218.
BATESON, WILLIAM: on protec-
tive method of concealment
amongst crabs, 171-2; on mimi-
cry amongst flies, 202.
Bears, Polar: colouration of, 189-93.
BECKER, A.: on sudden disap-
pearance of sousliks, 53.

BEDDARD, F. E.: on scientific ob-
servation, 182; on colouration of
snow-bunting, 188, of arctic foxes,
191, of bears, 191-2; on acci-
dental colouration with a varied
environment, 205; on coloura-
tion of puff-adder, 205-6; on
correlation between conspicuous
colouration and nauseous taste
amongst insects, 207-8; on warn-
ing colouration, 208; on nauseous
skin of caterpillar not protective,
214; on caterpillars being pinched
before eaten by birds, 215; on
non-universality of nauseous taste
in heliconius beskii, 219; on skin-
pigments the cause of nauseous
taste, 220; on influence of exter-
nal conditions on saturnia, 396;
on cause of colouration in ani-
mals, 404-5; on non-useful vari-
ation in insects, 411.
Beech extermination of, by birch,
110, 105.

Bees great increase in imported,

in New Zealand, 51; intelligence
in, 242-3.

Beetles co-operation amongst, 87;
unprotectiveness of nauseous
taste amongst, 218.
BELT, THOMAS: on variation, 4;
on bird-life in tropics, 22; on
indiscriminative slaughter of wari
by jaguars, 62; on protective
secretion of some insects, 166;
on protective colouration and
sagacity of locust, 173-4; on
protective mimicry of move-
ments by insects, 175; on mim-
etic colouration of spiders, 176;

BELT, THOMAS-(continued).

on mimicry, 195; on co-operation
amongst birds, 200; on corre-
lation between conspicuous col-
ouration and nauseous taste, 207;
on physiological barriers to
breeding amongst variants, 384.
BENNETT, A. W.: on mimicry in
relation to Natural Selection,
177-8; on probability of survival
of a favourable variant, 201.
Berberis, Spines of: 416.
Bifurcation of Species: 324-6.
"Bird-droppings": 174-5.
Birds dangers to life of eggs and
young, 61; sociability amongst,
88-9; as destroyers of insects,
164-5; protective colouration of,
173, 185; co-operation amongst,
200; loss of nest-building in-
stinct in, 262; faculties of very
young birds, 267; hybridisation
of, 353-4; variations in, 487-8;
evolution of, from reptile, 504.
Bisache habits of, 253-5.
Bison co-operation amongst, 94.
BLANCHARD, ÉMILE: on hybrisa-

tion of hares and rabbits, 355-6.
Blind Animals: evolution of, 377-9,
445-6.

BOISDUVAL, J. A.: on resemblance

amongst butterflies, 161.
BONNET: on instinct, 225-6.
BREE, DR. C. R.: on special crea-
tion, 471.
Breeding
to, 382-4.
BRONN, H. G.: on distinct species
never different from each other
in single characters but in many
parts, 342.

Physiological barriers

BROWNING, ROBT.: Pippa Passes
quoted, 422.

BRYANT, CAPT. (quoted by Darwin):
on sexual selection in seals, 39-40.
BRYDEN, H. A.: on the eland as
illustration of Law of Parsimony,
481.

BÜCHNER, PROF. LUDWIG on in-
stinct in butterflies, etc., 264;
in birds, 265.
Buck, Spike-horned: an instance
of abrupt structural modification,
359-60, 361-v. also Deer.

BUCKLAND, FRANK: on influence
of external conditions on oysters,
395.

BUFFON, G. L. L., COMTE DE: on

origin of species, 472.
Butterflies protective colouration
of, 173, 176-7; mimetic structure
and colouration of, 195; false
mimicry amongst, 196-7; in-
effectiveness of protective nau-
seous taste amongst, 218-9;
instinct in, 263-4-v. also Heli-
conidæ, Insects, Moths.

Cabbage: protective col-
ouration of, 174, 193-4; influence
of environment on colouration of
caterpillar of, 407-8.

Peacock influence of
external conditions on, 396.

Cabbage compensation of growth
in, 336.

CALDERWOOD, PROF. HENRY: on
instinct in lower animals, 235.
CANDOLLE, ALFRED DE (quoted by
Wallace) on usual abortiveness
of attempts to naturalize plants,
III; on geographical distribu-
tion of plants, 530; (quoted by
Darwin) on winged seeds never
found in fruits which do not
open, 342.

Capra negaceros: inherited effects
of habit in, 440.
CARLETON, WILL: Farm Ballads
quoted, 36.

Carp and Gold-fish: compared, 296.
CARPENTER, DR. W. B.: on in-

stinct in caterpillars, 232, in dogs,
243; on amoba, 237-8.
CARRINGTON, J. F.: on protective
colouration of cabbage butterfly,
174.

Carrot influence of external con-
ditions on, 398.

CARUS, DR. (quoted by Kirby) :
on sensitive life existent without
nerves, 238.

CATCHPOLE, MR.: on hybridisa-
tion, 386.

Caterpillars protective method of
concealment of, 172; protective
colouration, etc., 176, 185-6; pro-
tective nauseous taste of, 212-3;

Caterpillars-(continued).

hairy covering not always pro-
tective, 214; pinched by birds
before being eaten, 215; instinct
in, 232; use of chlorophyll by,
403-4, of tannin, 404-5; influence
of environment on colour of, 408;
conspicuous colouration of, not
due to Natural Selection, 522-3

ข. also Cabbage-butterfly,
Tiger moth.

Cats: absence of instinct in, 231;
instinct in, 231; instinct and
character in, 259.

of Mombas influence of
environment on, 423.
Cattle Black Cattle (Columbus') in
America, 51-2; independence of
character checked by struggle
for existence, 70; Mr. Romanes'
pictures of, as the outcome of
Artificial Selection, 151-2.

Niata variations in,

427-30.
Cattle-breeding: objects to be
aimed at, 142.

Cells: sensitiveness of, 573-6; fission
of, 576-7; conjugation, 578, 579-
80.
Centipede instinct in, 236; too
low to possess instinct, 235.
Chameleon experiment of, on bee
in absence of ordinary food, 214.
CHAMBERS, DR. ROBT.: on unity
of organic nature, 456, 457, 587;
on argument for organic evolution
from rudimentary structures, 458;
from geographical distribution,
458-9,459-60; from geology, 459;
from embryology, 460; from men-
tal constitution, 460-1; on special
creation, 461-2; on sentimental
objections to doctrine of descent
of man, 462; on variation in gold-
fish, 487; on arrested develop-
ment of tadpoles, 543.
CHAMBERS ENCYCLOPÆ-
DIA: on indiscriminate voracity
of pike, 62; on capture of prey
by lions, 63; on instinct in larva
of ant-lion, 234; on incubating
instinct in pythons, 265; on
hybridisation of hares and rab-
bits, 355.

PÆ-

Competition: v. Struggle for Exist-

ence.

Conformity to Type: 500-10.
Conjugation: 578, 579-80.
CONN, H. W.: on rudimentary
organs, 498.
Co-operation

among wild-cattle,
84-5; pelicans, 85,95; cranes, 86;
crabs, 86-7,87; beetles, 87; eagles,
90-1; vultures, 91; baboons, 93;
hawks, 93-4; bisons, 94; wild
swine, 94; mares, 94-5; rats, 95 ;
snails, 95; weasels, 95; mammals,
99-102; plants, 114-7; birds, 200;
in animal world, 123; defeats
"elimination of the worst," 93-
v. also Parental Devotion; Soci-
ability; Animal; Struggle for
Existence.

COPE, E. D.: on Survival of Fittest,

14; on mimetic colouration, 26;
on extinction of species, 316; on
non-identity of organic evolu-
tion and Natural Selection,
453.

CORNHILL MAGAZINE: on
co-operation in a Malagasy forest,
114-5, 116; on competition in
same, 116-7; on birds as des-
troyers of insects, 164-5.
COSTA (quoted by Darwin): on
influence of external conditions
of oyster, 395.

COTTON (of Christ Church, Oxon.):
his bees, in New Zealand, 51.
COURNOT: his definition of chance,
29.

Cow parental devotion of, 82.
Cox, RAMSAY: on influence of
external conditions on peacock-
butterfly, 396.

Crabs co-operation amongst, 86-7,
87; protective method of con-
cealment of, 171-2.

Cranes co-operation amongst, 86.
CROLL, DR. J.: his definition of
Natural Selection, 44.
Crossing: v. Hybridisation.
Crows hybridisation of, 353-4.
CUNNINGHAM, J. T.: on insect
workers and soldiers produced
from same kind of egg, 269.
CUVIER on his discovery of ex-
tinct types, 314.

Danaida: protective elasticity of,
166-7; acquisition of protective
nauseous secretions by, 217.
DARWIN, CHARLES: on variation,
4-5, 6, 10, 19, 146; on law of cor-
related variation, 334, 338-40,
341, 343-7; of instincts, 279-80,
284; of Niata ox, 427; of imported
plants, 534; on unuseful varia-
tions, 306, 410, 411; on useful
variations, 421, 422; on causes
of variability, 365-6; on natural
"Preservation," 15; on Struggle
for Existence, 17-9, 43, 76, 96, 97;
on Survival of Fittest, 23, 145;
amongst gulls, 443; amongst
owls, 443; amongst scarlet-run-
ners, 33-4, 139-40; on chance,
27-9, 60; on evolution of human
eye, 33; on Sexual Selection, 36,
37-8, 38-9; on romantic love in
animals, 38-9; on rate of increase
of man and elephants, 46; on
destruction of life as a check to
natural rate of increase, 47, 57;
his relation to Malthus, 50; on
increase in imported plants, 52;
on rarity of species, 57; on ac-
cidental destruction of life, 62;
on indiscriminate destruction of
life in seedlings, 66; on the
element of time in variation,
72-3; on animal sociability, 88;
on co-operation amongst ba-
boons, 93; amongst hawks, 93;
on Natural Selection, 104-5, 138,
146, 158; principle of Natural
Selection, 466, 485-6; difficulties
connected with Natural Selec-
tion, 467, 468; slow action of
Natural Selection, 399; on an-
alogy between Natural and
Artificial Selection, 131; on
"Methodical" and on "Uncon-
scious Selection, 136-8;
Artificial Selection, 139, 153;
in relation to sheep-breeding,
139; on power of Forelle-pear
to resist cold, 145; on protective
colouration among dragon-flies,
173; on influence of environ-
ment, 167, 395-6, 400-1, 431;
on cats, dogs and sheep, 423;
on feral pigs, 429; on proteus,

on

DARWIN, CHARLES (continued).
543; on influence of climate on
organic structure, 397-8; on in-
fluence of environment not pro-
ducing useful results, 412; on
change of environment in rela-
tion to sexual reproduction, 533;
on inutility of some organic
colouration, 204-5; on skin-pig-
ments the cause of nauseous
taste, 220; on instinct, 221, 228,
278-9, 279; on barking instinct in
dogs, 256; on instincts in ants,
269-70; on neuter insects, 267-8;
on sterile insects, 271; on vege-
table sensitiveness, 286; com-
parison of gold-fish and carp,
296; Transmutation of Species:
nature of conditions subordinate
to nature of organism, 310; in a
confined area due to Natural
Selection alone, 430; influence of
changed conditions on, not al-
ways rapid, 425-6, 430; on form
and habits of water-ouzel, 312;
on extinction of species, 316;
of horse, 318; on the petrel,
323-4; on co-existence of two
variants in same district, 326;
on law of compensation of growth
335-6; on law of homology, 337 ;
on evolution of elk from stag,
343, 345-6; on hybridisation,
350-2; on recent evolution of
ancon and merino ram, 358-9;
of breeds of dogs, 359; on An-
con, Jaguar and Pariah-dog, 359;
on abrupt structural modifica-
tions, 359-64; on antlers and
spike-horns, 362-3; on human
physical heredity, 364; on iso-
lation in breeding, 380-1; on
physiological barriers to breed-
ing amongst variants, 382; on
shape of skull in pig, 427-8; on
inherited effects of use and dis-
use, 438, 439-40, 441, 442; on
disuse as agent in formation of
rudimentary organs, 511; his
acceptance of Lamarckian prin-
ciples, 472; on ‘nihil per saltum,'
487; on rudimentary organs, 494,
496,497-8; on conformity of type,
500; on degeneration a result of