ROBINIA.

Poison, similar effect of, on animals and
plants, 484.

Pollen of fir-trees, 203.

Poole, Col., on striped hemionus, 163.
Potamogeton, 387.

Prestwich, Mr., on English and French
eocene formations, 328.
Primrose, 49.

sterility of, 247.

Primula, varieties of, 49.
Proteolepas, 148.

Proteus, 139.

Psychology, future progress of, 489.

Q.

Quagga, striped, 165.
Quince, grafts of, 262.

R.

Rabbit, disposition of young, 215.
Races, domestic, characters of, 16.
Race-horses, Arab, 35.

-, English, 356.

Ramond on plants of Pyrenees, 368.
Ramsay, Prof., on thickness of the
British formations, 284.

-, on faults, 285.

Ratio of increase, 63.

Rats, supplanting each other, 76.
acclimatisation of, 141.

-, blind in cave, 137.
Rattle-snake, 201.
Reason and instinct, 208.
Recapitulation, general, 459.
Reciprocity of crosses, 258.
Record, geological, imperfect, 279.
Rengger on flies destroying cattle, 72.
Reproduction, rate of, 63.
Resemblance to parents in mongrels and
hybrids, 273.

Reversion, law of inheritance, 14.

in pigeons to blue colour, 160.
Rhododendron, sterility of, 251.
Richard, Prof., on Aspicarpa, 417.
Richardson, Sir J., on structure of
squirrels, 180.

on fishes of the southern hemi-
sphere, 376.

Robinia, grafts of, 262.

on neuter ants, 239.

-, Mr., of Jordan Hill, on the de-
gradation of coast-rocks, 283.
Snap-dragon, 161.

Somerville, Lord, on selection of sheep,
31.

Sorbus, grafts of, 262.

Spaniel, King Charles's breed, 35.
Species, polymorphic, 46.

~, common, variable, 53.

in large genera variable, 54.
-, groups of, suddenly appearing,
302, 307.

beneath Silurian formations, 307.
successively appearing, 312.

changing simultaneously through-
out the world, 322.

Spencer, Lord, on increase in size of
cattle, 35.

Sphex, parasitic, 218.

Spiders, development of, 442.
Spitz-dog crossed with fox, 268.
Sports in plants, 9.

Sprengel, C. C., on crossing, 98.

on ray-florets, 145.

STRUCTURE,

Structure, degrees of utility of, 201.
Struggle for existence, 60.
Succession, geological, 312.

Succession of types in same areas, 338.

Swallow, one species supplanting an-
other, 76.
Swim-bladder, 190.
System, natural, 413.

Tail of giraffe, 195.

T.

of aquatic animals, 196.
-, rudimentary, 454.
Tarsi deficient, 135.

Tausch on umbelliferous flowers, 146.
Teeth and hair correlated, 144.

-, embryonic, traces of, in birds,
450.

—, rudimentary, in embryonic calf,
450, 480.

Tegetmeier, Mr., on cells of bees, 228,
233.

Temminck on distribution aiding classi-
fication, 419.

Thouin on grafts, 262.
Thrush, aquatic species of, 185.

-, mocking, of the Galapagos, 402.
, young of, spotted, 439.

nest of, 243.

Valenciennes on fresh-water fish, 384.
Variability of mongrels and hybrids,
274.

Variation under domestication, 7.

caused by reproductive system
being affected by conditions of life, 8.
under nature, 44.

laws of, 131.

Variations appear at corresponding ages,
14, 86.

analogous in distinct species,

159.

struggle between, 75.

Varieties, natural, 44.

domestic, extinction of, 111.

transitional, rarity of, 172.

when crossed, fertile, 268.
when crossed, sterile, 269.
classification of, 423.

Verbascum, sterility of, 251.

varieties of, crossed, 271.
Verneuil, M. de, on the succession of

species, 325.

Viola tricolor, 73.

Watson, Mr. H. C., on range of varieties

of British plants, 58.

9

on acclimatisation, 140.

on flora of Azores, 363.

on Alpine plants, 368, 376.

on rarity of intermediate varie-
ties, 176.

Weald, denudation of, 285.
Web of feet in water-birds, 185.
West Indian islands, mammals of, 396.
Westwood on species in large genera
being closely allied to others, 57.

on the tarsi of Engidæ, 157.
on the antennæ of hymenopterous
insects, 415.

Wheat, varieties of, 113.

White Mountains, flora of, 365.

Wings, reduction of size, 134.

DEUTSCHES

MUNCHEN