This page has been validated.
pigs.
INDEX.
polygamy.
669

of the crop of both parents, 163; changes of plumage in, 229; transmission of sexual peculiarities in, 230; Belgian, with black-streaked males, 231, 238, 446; changing colour after several moultings, 238; numerical proportion of the sexes in, 247; cooing of, 374; variations in plumage of, 385; display of plumage by male, 402; local memory of, 411; antipathy of female, to certain males, 418; pairing of, 418; profligate male and female, 418; wing-bars and tail-feathers of, 427; suppositious breed of, 445; pouter and carrier, peculiarities of, predominant in males, 447; nidification of, 453; Australian, 458; immature plumage of the, 467.

  • Pigs, origin of the improved breeds of, 177; numerical proportion of the sexes in, 247; stripes of young, 464, 546; tusks of miocene, 521; sexual preference shewn by, 525.
  • Pike, American, brilliant colours of the male, during the breeding season, 340.
  • ——, reasoning powers of, 75; male, devoured by females, 249.
  • Pike, L. O., on the psychical elements of religion, 95.
  • Pimelia striata, sounds produced by the female, 306.
  • Pinel, hairiness in idiots, 36.
  • Pintail, drake, plumage of, 393; pairing with a wild duck, 415.
  • —— Duck, pairing with a wigeon, 414.
  • Pipe-fish, filamentous, 344; marsupial receptacles of the male, 346.
  • Pipits, moulting of the, 392.
  • Pipra, modified secondary wing-feathers of male, 378.
  • —— deliciosa, 378, 379.
  • Pirates stridulus, stridulation of, 281.
  • Pitcairn island, half-breeds on, 190.
  • Pithecia leucocephala, sexual differences of colour in, 537.
  • —— Satanas, beard of, 531, 532; resemblance of, to a negro, 604.
  • Pits, suborbital, of Ruminants, 529.
  • Pittidæ, nidification of, 453.
  • Placentata, 157.
  • Plagiostomous fishes, 331.
  • Plain-wanderer, Australian, 473.
  • Planariœ, bright colours of some, 260.
  • Plantain-eaters, colours and nidification of the, 455; both sexes of, equally brilliant, 460.
  • Plants, cultivated, more fertile than wild, 45; Nägeli, on natural selection in, 61; male flowers of, mature before the female, 212; phenomena of fertilisation in 222.
  • Platalea, 374; change of plumage in, 461.
  • Platyblemnus, 289.
  • Platycercus, young of, 481.
  • Platyphyllum concavum, 283, 286.
  • Platyrrhine monkeys, 153.
  • Platysma myoides, 13.
  • Plecostomus, head-tentacles of the males of a species of, 338.
  • —— barbatus, peculiar beard of the male, 338.
  • Plectropterus gambensis, spurred wings of, 364.
  • Ploceus, 370, 375, 405.
  • Plovers, wing-spurs of, 365; double moult in, 392.
  • Plumage, changes of, inheritance of, by fowls, 229; tendency to analogous variation in, 385; display of, by male birds, 394, 402; changes of, in relation to season, 462; immature, of birds, 464, 465; colour of, in relation to protection, 489.
  • Plumes on the head in birds, difference of, in the sexes, 451.
  • Pneumora, structure of, 286.
  • Podica, sexual difference in the colour of the irides of, 425.
  • Poeppig, on the contact of civilised and savage races, 183.
  • Poison, avoidance of, by animals, 80.
  • Poisonous fruits and herbs avoided by animals, 66.
  • Poisons, immunity from, correlated with colour, 193.
  • Polish fowls, origin of the crest in, 231.
  • Pollen and van Dam, on the colours of, Lemur macaco, 537.
  • Polyandry, 593; in certain Cyprinidæ, 249; among the Elateridæ, 253.
  • Polydactylism in man, 37.
  • Polygamy, influence of, upon sexual selection, 216; superinduced by