i. 269.

Papaper bracteatum, i. 272.
Paraguay, cattle destroyed by flies,
i. 89.
Parasites, i. 334.

Partridge, with ball of earth at-
tached to foot, ii. 148.
Parts greatly developed, variable,
i. 185.

Parus major, i. 220.
Passiflora, ii. 7.

Peaches in United States, i. 104.
Pear, grafts of, ii. 18.
Pedicellariæ, i. 298.
Pelagornium, flowers of, i. 180.
sterility of, ii. 7.
Pelvis of women, i. 178.
Peloria, i. 180.
Period, glacial, ii. 151.
Petrels, habits of, i. 221.
Phasianus, fertility of hybrids, ii. 9.
Pheasant, young, wild, L. 329.
Pictet, Prof., on groups of species
suddenly appearing, ii. 77.

on rate of organic change, ii. 90.
on continuous succession of
genera, ii. 93.

on change in latest tertiary
forms, ii. 71.

on close alliance of fossils in
consecutive formations, ii. 114.

on early transitional liuks, ii.

78.
Pierce, Mr., on varieties of wolves,
i. 111.

Pigeons with feathered feet and skin
between toes, i. 14.

breeds described, and origin

of, i. 23.

47.

breeds of, how produced, i. 44,

destroyed by insects, i. 83.
in midst of range, have to
struggle with other plants, i. 95.
nectar of, i. 114.

174.

fleshy, on sea-shores, i. 166.
climbing, i. 230, 305.
fresh-water, distribution of, ii.

low in scale, widely distri-
buted, ii. 196.
Pleuronectidæ, their structure, i.
290.

Plumage, laws of change in sexes
of birds, i. 109.

Plums in the United States, i. 104.
Pointer dog, origin of, i. 40.
habits of, i. 327.

Poison not affecting certain coloured
animals, i. 13.
-, similar effect of, on animals
and plants, ii. 299.
Pollen of fir-trees, i. 257.

transported by various means,
i. 241, 252.

Pollinia, their development, i. 304.
Polyzoa, their avicularia, i. 301.
Poole, Col., on striped hemionus, i.

Ramond, on plants of Pyrenees, ii.

153.

Ramsay, Prof., on subaerial denu-
dation, ii. 53.

on thickness of the British
formations, ii. 55, 56.

-, on faults, ii. 55.
Ramsay, Mr., on instincts of cuckoo,
i. 333.

Ratio of increase, i. 79.
Rats supplanting each other, i. 93.
acclimatisation of, i. 175.
-, blind, in cave, i. 171.
Rattle-snake, i. 254.
Reason and instinct, i. 319.
Recapitulation, general, ii. 267.
Reciprocity of crosses, ii. 14.
Record, geological, imperfect, ii. 48.
Rengger, on flies destroying cattle,
i. 89.

Reproduction, rate of, i. 79.
Resemblance, protective, of insects,
i. 283.

198.

in pigeons, to blue colour, i.
Rhododendron, sterility of, ii. 7, 8.
Richard, Prof., on Aspicarps, ii. 209.
Richardson, Sir J., on structure of
squirrels, i. 216.

-, on fishes of the southern hemi-
sphere, ii. 164.
Robinia, grafts of, ii. 19.
Rodents, blind, i. 170.

Rogers, Prof., Map of N. America,
ii 65.

Rudimentary organs, ii. 255.
Rudiments important for classifica-
tion, ii. 207.

Rütimeyer, on Indian cattle, i. 21;
ii. 10.

S.

Salamandra atra, ii. 256.
Saliva used in nests, i. 355.
Salvin, Mr., on the beaks of ducks,
i. 287.

Sageret, on grafts, ii. 18.
Salmons, males fighting, and hooked
jaws of, i. 108.

Salt water, how far injurious to
seeds, ii. 142.

not destructive to land-shells,
ii. 187.

Salter, Mr., on early death of hybrid
embryos, ii. 23.

Saurophagus sulphuratus, i. 220.
Schacht, Prof., on Phyllotaxy, i.

270.

Schiödte, on blind insects, i. 172.
on flat-fish, i. 290.

Schlegel, on snakes, i. 178.
Schöbl, Dr., on the ears of mice, i.
268.

Scott, J., Mr., on the self-sterility of
orchids, ii. 7.

-, on the crossing of varieties of
verbascum, ii. 38.
Sea-water, how far injurious to
seeds, ii. 142.

not destructive to land-shells,
ii. 187.

Sebright, Sir J., on crossed animals,
i. 23.

Sedgwick, Prof., on groups of spe-

cies suddenly appearing, ii. 77.
Seedlings destroyed by insects, i.

83.

Seeds, nutriment in, i. 94.

winged, i. 181.

means of dissemination, i.
240, 252; ii. 146.

-, power of resisting salt water,
ii. 143.

in crops and intestines of
birds, ii. 146.

eaten by fish, ii. 146, 176.
in mud, ii. 175.

hooked, on islands, ii. 181:

Selection of domestic products, i. 34.

-, principle not of recent origin,
i. 39.

unconscious, i. 39.

-, natural, i. 97.

sexual, i. 107.

objections to term, i. 99.

natural, has not induced steri-

lity, ii. 20.

Shells, fresh-water, dispersal of, ii.
173.

of Madeira, ii. 180.

land, distribution of, ii. 180.
land, resisting salt water, ii.
187.
Shrew-mouse, ii. 218.

Silene, infertility of crosses, ii. 14.
Silliman, Prof., on blind rat, i. 171.
Sirenia, their affinities, ii. 108.
Sitaris, metamorphosis of, ii. 252.
Skulls of young mammals, i. 248;
ii. 235.

Slave-making instinct, i. 336.
Smith, Col. Hamilton, on striped
horses, i. 200.

Mr. Fred., on slave-making
ants, i. 337.

on neuter ants, i. 360.
Smitt, Dr., on the Polyzoa, i. 301.
Snake with tooth for cutting through
egg-shell, i. 334.

Somerville, Lord, on selection of
sheep, i. 35.
Sorbus, grafts of, ii. 19.
Sorex, ii. 218.

Spaniel, King Charles's breed, i. 40.
Specialisation of organs, i. 152.
Species, polymorphic, i. 54.
- dominant, i. 67.

, common, variable, i. 66.

in large genera variable, i. 69.
-, groups of, suddenly appear-
ing, ii. 77, 82.

beneath Silurian formations,
ii. 84.

successively appearing, ii. 89.
changing simultaneously
throughout the world, ii. 100.
Spencer, Lord, on increase in size of
cattle, i. 40.

Herbert, Mr., on the first steps
in differentiation, i. 155.

on the tendency to an equili-
brium in all forces, ii. 29.
Sphex, parasitic, i. 336.
Spiders, development of, ii. 245.
Sports in plants, i. 11.
Sprengel, C. C., on crossing, i. 119.
on ray-florets, i. 180.
Squalodon, ii. 108.

Squirrels, gradations in structure, i.

216.

Staffordshire, heath, changes in, i.
87.

Stag-beetles, fighting, i. 108.

Star-fishes, eyes of, i. 225.

325.

Sting of bee, i. 256.

Stocks, aboriginal, of domestic ani-
mals, i. 22.

Strata, thickness of, in Britain, ii. 55.
Stripes on horses, i. 199.
Structure, degrees of utility of, i. 249.
Struggle for existence, i. 75.
Succession, geological, ii. 89.

of types in same areas, ii 121.
Swallow, one species supplanting
another, i. 93.

Swaysland, Mr., on earth adhering
to the feet of migratory birds, ii.

148.

Swifts, nests of, i. 355.
Swim-bladder, i. 230.

Switzerland, lake habitations of, i.
20.

System, natural, ii. 204.

T.

Tail of giraffe, i. 245.

of aquatic animals, i. 246.
-, prehensile, i. 294.

rudimentary, ii. 260.

Tanais, dimorphic, i. 55.
Tarsi, deficient, 168.

Tausch, Dr., on umbelliferæ, i. 271.
Teeth and hair correlated, i. 179.

rudimentary, in embryonic,
calf, ii. 255, 292.
Tegetmeier, Mr., on cells of bees, i.
346, 352.

Temminck, on distribution aiding
classification, ii. 211.
Tendrils, their development, i. 305.
Thompson, Sir W., on the age of
the habitable world, ii. 83.

-, on the consolidation of the
crust of the earth, ii. 275.

Thouin, on grafts, ii. 19.
Thrush, aquatic species of, i. 222.
-, mocking, of the Galapagos, ii.

192.

-, young of, spotted, ii. 241.
nest of, i. 364.

Thuret, M., on crossed fuci, ii. 15.
Thwaites, Mr. on acclimatisation,
i. 174.
Thylacinus, ii. 220.
Tierra del Fuego, dogs of, i. 328.
plants of, ii. 169.
Timber-drift, ii. 145.
Time, lapse of, ii. 51.

by itself not causing modifica-
tion, i. 126.
Titmouse, i. 220.

Toads on islands, ii. 182.
Tobacco, crossed varieties of, ii. 38.
Tomes, Mr., on the distribution of
bats, ii. 184.

Transitions in varieties rare, i. 208.
Traquair, Dr., on flat-fish, i. 293.
Trautschold, on intermediate varie-
ties, ii. 66.

Trees on islands belong to peculiar
orders, ii. 182.

with separated sexes, i. 123.
Trifolium pratense, i. 90, 117.
incarnatum, i. 117.
Trigonia, ii. 99.
Trilobites, ii. 83.

sudden extinction of, ii. 99.
Trimen, Mr., on imitating-insects,
ii. 224.

Trimorphism in plants, i. 55; ii. 29.
Troglodytes, i. 364.

Tuco-tuco, blind, i. 170.

Tumbler pigeons, habits of, heredi-
tary, i. 327.

young of, ii. 248.

Turkey-cock, tuft of hair on breast,
i. 110.

naked skin on head, i. 248.
young of, instinctively wild,
i. 329.
Turnip and cabbage, analogous
variations of, i. 195.
Type, unity of, i. 260, 261.
Types, succession of, in same areas,
ii. 121.
Typotherium, ii. 108.

U.

Udders enlarged by use, i. 12.
rudimentary, ii. 256.

Valenciennes, on fresh-water fish,
ii. 173.
Variability of mongrels and hy-
brids, ii. 39.
Variation under domestication, i. 8.
caused by reproductive system
being affected by conditions of
life, i. 10.

under nature, i. 51.

laws of, i. 164.

correlated, i. 13, 177, 248.
Variations appear at corresponding
ages, i. 16, 105.

analogous in distinct species,
i. 193.

Varieties, natural, i. 50.

struggle between, i. 93.
domestic, extinction of, i. 134.
transitional, rarity of, i. 208.
when crossed, fertile, ii. 34.
Varieties, when crossed, sterile, ii. 37.
classification of, ii. 215.
Verbascum, sterility of, ii. 7.

varieties of crossed, ii. 38.
Verlot, M., on double stocks, i. 358.
Verneuil, M. de, on the succession
of species, ii. 103.

Vibracula of the Polyzoa, i. 301.
Viola, small imperfect flowers of,
i. 269.

tricolor, i. 90.
Virchow, on the structure of the
crystalline lens, i. 227.
Virginia, pigs of, i. 104.

Volcanic islands, denudation of, ii.
54.

Vulture, naked skin on head, i. 247.

W.

Wading-birds, ii. 175.

on the walking-stick insect, i.

on laws of geographical dis-
tribution, ii. 139.

185.

on the Malay Archipelago, ii.

on mimetic animals, ii. 224.
Walsh, Mr. B. D., on phytophagic
forms, i. 60.

on equal variability, i. 195.
Water, fresh, productions of, ii. 171.
Water-hen, i. 222.

Waterhouse, Mr., on Australian
marsupials, i. 140.

on greatly developed parts
being variable, i. 185.

on the cells of bees, i. 343.
-, on general affinities, ii. 227.
Water-ouzel, i. 222.

Watson, Mr. H. C., on range of
varieties of British plants, i. 57,
73.

on acclimatisation, i. 134.
on flora of Azores, ii. 149.
on Alpine plants, ii. 153.
-, on rarity of intermediate va-
rieties, i. 212.

on convergence, i. 156.

on the indefinite multiplica-
tion of species, i. 157.
Weale, Mr., on locusts transporting
seeds, ii. 147.

Web of feet in water-birds, i. 223.
Weismann, Prof., on the causes of
variability, i. 8.

on rudimentary organs, ii. 260.
West Indian Islands, mammals of,
ii. 185.

Westwood, on species in large gen-
era being closely allied to others,
i. 71.

on the tarsi of Engidæ, i. 192.
on the antennæ of hymeno-
pterous insects, ii. 207.