Hooker, Dr., on acclimatisation of Hima
layan trees, 127.

on flowers of umbelliferæ, 132.
on glaciers of Himalaya, 324.
on algae of New Zealand, 327.

on vegetation at the base of the
Himalaya, 329.

on plants of Tierra del Fuego, 326,
329.

on Australian plants, 327, 347.

on relations of flora of South Amer-
ica, 330.

on flora of the Antarctic lands, 341,
347.

on the plants of the Galapagos, 341,
347.

Hooks on bamboos, 176.

to seeds on islands, 342.

Horner, Mr., on the antiquity of Egyp-
tians, 23.

Horns, rudimentary, 394.

Horse, fossil, in La Plata, 278.

Horses destroyed by flies in La Flata, 70.
striped, 147.

proportions of, when young, 386.
Horticulturists, selection applied by, 35.
Huber on cells of bees, 205.

P., on reason blended with instinct,
186.

on habitual nature of instincts, 186.
on slave-making ants, 195.

on Melipona domestica, 200.

Humble-bees, cells of, 200.

Hunter, J., on secondary sexual charac-
ters, 136.

Hutton, Captain, on crossed geese, 224.
Huxley, Prof., on structure of hermaph-
rodites, 94.

on embryological succession, 295.
on homologous organs, 381.

on the development of aphis, 384.
Hybrids and mongrels compared, 239.
Hybridism, 217.

Hydra, structure of, 170.

Jussieu on classification, 363.

Kentucky, caves of, 125.
Kerguelen-land, flora of, 331, 347.
Kidney-bean, acclimatisation of, 129.
Kidneys of birds, 131.

Kirby on tarsi deficient in beetles, 123.
Knight, Andrew, on cause of variation, 14.
Kolreuter on the barberry, 92.

on sterility of hybrids, 218.
on reciprocal crosses, 228.

on crossed varieties of nicotiana, 239.
on crossing male and hermaphrodite
flowers, 392.

Lamarck on adaptive characters, 371.
Land-shells, distribution of, 346.

of Madeira, naturalised, 350.

Languages, classification of, 367.
Lapse, great, of time, 247.

Larvæ, 382.

Laurel, nectar secreted by the leaves, 88.

Laws of variation, 120.

Leech, varieties of, 73.

Madeira, fossil land-shells of, 296.
birds of, 340.

Magpie tame in Norway, 189.
Maize, crossed, 238.

Malay Archipelago compared with Eu-
rope, 262.

mammals of, 344.
Malpighiaceæ, 363.

Mammæ, rudimentary, 392.

Mammals, fossil, in secondary formation,

265.

insular, 343.

Man, origin of races af, 178.
Manatee, rudimentary nails of, 394.
Marsupials of Australia, 107.

fossil species of, 296.

Martens, M., experiment on seeds, 315.
Martin, Mr. W. C., on striped mules, 148.
Matteuchi on the electric organs of rays,

172.

Lepidosiren, 100, 288.

Life, struggle for, 60.

Linnæus, aphorism of, 360.

Lingula, Silurian, 268.

Lion, mane of, 84.

young of, striped, 382.

Lobelia fulgens, 71, 92.

Lobelia, sterility of crosses, 221.
Loess of the Rhine, 335.

Lowness of structure connected with va-
riability, 135.

Lowness, related to wide distribution, 353.
Lubbock, Mr., on the nerves of coccus, 47.
Lucas, Dr. P., on inheritance, 19.

on resemblance of child to parent,
242.

Lund and Clausen on fossils of Brazil, 296.
Lyell, Sir C., on the struggle for existence,
61.

on modern changes of the earth, 90.
on measure of denudation, 249.
on a carboniferous land-shell, 253.
on fossil whales, 265.

on strata beneath Silurian system,

268.

on the imperfection of the geological
record, 271.

on the appearance of species, 273.
on Barrande's colonies, 274.

on tertiary formations of Europe and
North America, 282.

on parallelism of tertiary formations,
287.

on transport of seeds by icebergs,
317.

on great alternations of climate, 332.
on the distribution of fresh-water
shells, 336.

on land-shells of Madeira, 350.
Lyell and Dawson on fossilised trees in
Nova Scotia, 259.

Macleay on analogical characters, 371.
Madeira, plants of, 100.

beetles of, wingless, 124.

acclimatisation of, 128.

Migration, bears on first appearance of

fossils, 259.

Mongrels, fertility and sterility of, 236.
and hybrids compared, 239.
Monkeys, fossil, 265.
Monocanthus, 369.

Mons, Van, on the origin of fruit-trees, 32.
Moquin-Tandon on sea-side plants, 121.
Morphology, 377.

Mozart, musical powers of, 186.
Mud, seeds in, 337.
Mules, striped, 148.

Müller, Dr. F., on Alpine Australian
plants, 327.

Murchison, Sir R., on the formations of
Russia, 253.

on azoic formations, 268.
on extinction, 277.
Mustela vison, 161.
Myanthus, 369.
Myrmecocystus, 211.
Myrmica, eyes of, 213.

Nails, rudimentary, 393.

Natural history, future progress of, 419.
selection, 77.
system, 360.

Naturalisation of forms distinct from the
indigenous species, 107.
in New Zealand, 180.
Nautilus, Silurian, 268.
Nectar of plants, 88.
Nectaries, how formed, 88.
Nelumbium luteum, 337.

Nodules, phosphatic, in azoic rocks, 269.

Oak, varieties of, 51.
Onites apelles, 123.
Orchis, pollen of, 173.

Organs of extreme perfection, 167.
electric, of fishes, 172
of little importance, 174.
homologous, 377.

rudiments of, 391.

Ornithorhynchus, 100, 362.
Ostrich not capable of flight, 123.
habit of laying eggs together, 194.
American, two species of, 305.
Otter, habits of, how acquired, 161.
Ouzel, water, 166.

Owen, Prof., on birds not flying, 123.
on vegetative repetition, 135.

on variable length of arms in ourang-
outang, 136.

on the swim-bladder of fishes, 171.
on electric organs, 172.

on fossil horse of La Plata, 279.

on relations of ruminants and pachy-
derms, 288.

on fossil birds of New Zealand, 296.
on succession of types, 296.
on affinities of the dugong, 361.
on homologous organs, 378.

on the metamorphosis of cephalo-
pods and spiders, 384.

Pacific Ocean, faunas of, 304.

Paley on no organ formed to give pain,

179.

Philippi on tertiary species in Sicily, 273.
Pictet, Prof., on groups of species sudden.
ly appearing, 264, 267.

on rate of organic change, 274.
on continuous succession of genera,
277.

on close alliance of fossils in con-
secutive formations, 293.

on embryological succession, 295.
Pierce, Mr., on varieties of wolves, 87.
Pigeons with feathered feet and skin be-
tween toes, 18.

breeds described, and origin of, 25.
breeds of, how produced, 41, 44.
tumbler, not being able to get out of
egg, 83.

reverting to blue color, 144.
instinct of tumbling, 191.

carriers, killed by hawks, 315.
young of, 387.

Pistil, rudimentary, 392.

Plants, poisonous, not affecting certain
coloured animals, 18:

selection applied to, 36.

gradual improvement of, 40.

not improved in barbarous countries,
40.

destroyed by insects, 66.

in midst of range, have to struggle
with other plants, 75.

nectar of, 87.

fleshy, on sea-shores, 121.

fresh-water, distribution of, 336.

low in scale, widely distributed, 353.
Plumage, laws of change in sexes of birds,

Robinia, grafts of, 231.

Rodents, blind, 125.

Rudimentary organs, 391.

Sphex, parasitic, 195.

362.

Sageret on grafts, 231.

Salmons, males fighting, and hooked jaws
of, 84.

Salt water, how far injurious to seeds, 312.
Saurophagus sulphuratus, 164.
Schiödte on blind insects, 126.
Schlegel on snakes, 131.

Sea-water, how far injurious to seeds, 812.
Sebright, Sir J., on crossed animals, 25,

on selection of pigeons, 34.

Sedgwick, Prof., on groups of species sud-
denly appearing, 264.

Seedlings destroyed by insects, 66
Seeds, nutriment in, 75.
winged, 133.

power of resisting salt water, 312.
in crops and intestines of birds, 315.
eaten by fish, 316, 337.

in mud, 337.

hooked, on islands, 341.

Selection of domestic products, 33.
principle not of recent origin, 36.
unconscious, 37.

natural, 77.

sexual, 83.

to, 95.

Spitz-dog crossed with fox, 236.
Sports in plants, 16.

Sprengle, C. C., on crossing, 92.

on ray-florets, 132.

Squirrels, gradations in structure, 162.
Staffordshire, heath, changes in, 70.
Stag-beetles, fighting, 84.

Sterility from changed conditions of life,

16.

of hybrids, 218.

laws of, 225.
causes of, 232.

from unfavourable conditions, 234.
of certain varieties, 237.

St. Helena, productions of, 339.

St. Hilaire, Aug., on classification, 364,
St. John, Mr., on habits of cats, 86.
Sting of bee, 180.

Stocks, aboriginal, of domestic animals, 23.
Strata, thickness of, in Britain, 249.
Stripes on horses, 147.

Structure, degrees of utility of, 179.
Struggle for existence, 60.

Succession, geological, 273.

Succession of types in same areas, 295.
Swallow, one species supplanting another,

74.

Sexes, relations of, 83.

Sexual characters variable, 141.

selection, 83.

Sheep, Merino, their selection, 35.

System, natural, 360.

Tail of giraffe, 174.

of aquatic animals, 175.
rudimentary, 394.

analogous in distinct species, 144.

Varieties, natural, 46.

struggle between, 73.

domestic, extinction of, 104.
transitional, rarity of, 154.
when crossed, fertile, 236.

when crossed, sterile, 237.
classification of, 368.

Verbascum, sterility of, 222.
varieties of, crossed, 238.

pials, 108.

Weald, denudation of, 250.
Web of feet in water-birds, 166.

West Indian islands, mammals of, 344.
Westwood on species in large genera being
closely allied to others, 57.

on the tarsi of Engidæ, 142.

on the antennæ of hymenopterous
insects, 362.

Whales, fossil, 265.

Wheat, varieties of, 105.

White Mountains, flora of, 318.
Wings, reduction of size, 123.

of insects homologous with bran-
chiæ, 171.

rudimentary, in insects, 391.
Wolf crossed with dog, 191.

of Falkland Isles, 343.

Wollaston, Mr., on varieties of insects, 50.
on fossil varieties of land-shells in
Madeira, 53.

on colours of insects on sea-shore,
121.

on wingless beetles, 124.

on rarity of intermediate varieties,
158.

on insular insects, 339.

on land-shells of Madeira, natu-
ralised, 350.

Wolves, varieties of, 86.
Woodpecker, habits of, 165.

green colour of, 176.

Woodward, Mr., on the duration of spe-
cific forms, 257.

on the continuous succession of gen-
era, 276.

on the succession of types, 296.

World, species changing simultaneously

throughout, 282.

Wrens, nest of, 215.

cies, 284.

Viola tricolor, 71.

Volcanic islands, denudation of, 249.

Vulture, naked skin on head, 176.

Wading-birds, 337.

on sub-breeds of sheep, 39.

on rudimentary horns in young cat-
tle, 394.