V.

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. Varieties, natural, 44. ----, struggle between, 75. ----, 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. {502} Volcanic islands, denudation of, 285. Vulture, naked skin on head, 197.

W.

Wading-birds, 386. Wallace, Mr., on origin of species, 2. ----, on law of geographical distribution, 355. ----, on the Malay Archipelago, 395. Wasp, sting of, 202. Water, fresh, productions of, 383. Water-hen, 185. Waterhouse, Mr., on Australian marsupials, 116. ----, on greatly developed parts being variable, 150. ----, on the cells of bees, 225. ----, on general affinities, 429. Water-ouzel, 185. Watson, Mr. H. C, on range of varieties of British plants, 58. ----, on acclimatisation, 140. ----, on flora of Azores, 363. ----, on Alpine plants, 368, 376. ----, on rarity of intermediate varieties, 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. ---- of insects homologous with branchiæ, 191. ----, rudimentary, in insects, 450. Wolf crossed with dog, 214. ---- of Falkland Isles, 394. Wollaston, Mr., on varieties of insects, 48. ----, on fossil varieties of land-shells in Madeira, 52. ----, on colours of insects on sea-shore, 132. ----, on wingless beetles, 135. ----, on rarity of intermediate varieties, 176. ----, on insular insects, 389. ----, on land-shells of Madeira, naturalised, 402. Wolves, varieties of, 90. Woodpecker, habits of, 184. ----, green colour of, 197. Woodward, Mr., on the duration of specific forms, 294. ----, on the continuous succession of genera, 316. ----, on the succession of types, 339. World, species changing simultaneously throughout, 322. Wrens, nest of, 243.

Y.

Youatt, Mr., on selection, 31. ----, on sub-breeds of sheep, 36. ----, on rudimentary horns in young cattle, 454.

Z.

Zebra, stripes on, 163.

THE END.

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LONDON: PRINTED BY WILLIAM CLOWES AND SONS, STAMFORD STREET, AND CHARING CROSS.

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Corrections made to printed original.

p. 133. "the slightest use to a being": 'slighest' in original.

p. 193. "as Matteucci asserts": 'Matteucei' in original (the index correctly has Matteucci).

p. 201. "deposited in the living bodies of other insects": 'depo-sisted' (across page break) in original.

p. 315. "the newly-formed fantail": 'faintail' in original.

p. 398. "the volcanic nature of the soil": 'volanic' in original.

p. 403. "Madeira and the adjoining islet": 'Maderia' in original; and so in "from Porto Santo to Madeira".

p. 442. "the same individual embryo": 'indivividual' in original.

p. 458. "innumerable species, genera, and families": 'inumerable' in original.

p. 490. "Inheritance which is almost implied by reproduction": 'Inheritrnce' in original.