Resemblances, small, between man and the apes.
Retrievers, exercise of reasoning faculties by.
Revenge, manifested by animals.
Reversion, perhaps the cause of some bad dispositions.
Rhagium, difference of colour in the sexes of a species of.
Rhamphastos carinatus.
Rhea Darwinii.
Rhinoceros, nakedness of; horns of; horns of, used defensively; attacking white or grey horses.
Rhynchaea, sexes and young of.
Rhynchaea australis.
Rhynchaea bengalensis.
Rhynchaea capensis.
Rhythm, perception of, by animals.
Richard, M., on rudimentary muscles in man.
Richardson, Sir J., on the pairing of Tetrao umbellus; on Tetrao urophasianus; on the drumming of grouse; on the dances of Tetrao phasianellus; on assemblages of grouse; on the battles of male deer; on the reindeer; on the horns of the musk-ox; on antlers of the reindeer with numerous points; on the moose; on the Scotch deerhound.
Richter, Jean Paul, on imagination.
Riedel, on profligate female pigeons.
Riley, Mr., on mimicry in butterflies; bird's disgust at taste of certain caterpillars.
Ring-ouzel, colours and nidification of the.
Ripa, Father, on the difficulty of distinguishing the races of the Chinese.
Rivalry, in singing, between male birds.
River-hog, African, tusks and knobs of the.
Rivers, analogy of, to islands.
Roach, brightness of the male during breeding-season.
Robbery, of strangers, considered honourable.
Robertson, Mr., remarks on the development of the horns in the roebuck and red deer.
Robin, pugnacity of the male; autumn song of the; female singing of the; attacking other birds with red in their plumage; young of the.
Robinet, on the difference of size of the male and female cocoons of the silk-moth.
Rodents, uterus in the; absence of secondary sexual characters in; sexual differences in the colours of.
Roe, winter changes of the.
Rohfs, Dr., Caucasian features in negro; fertility of mixed races in Sahara; colours of birds in Sahara; ideas of beauty amongst the Bornuans.
Rolle, F., on the origin of man; on a change in German families settled in Georgia.
Roller, harsh cry of.
Romans, ancient, gladiatorial exhibitions of the.
Rook, voice of the.
Rossler, Dr., on the resemblance of the lower surface of butterflies to the bark of trees.
Rostrum, sexual difference in the length of in some weevils.
Royer, Madlle., mammals giving suck.
Rudimentary organs, origin of.
Rudiments, presence of, in languages.
Rudolphi, on the want of connexion between climate and the colour of the skin.
Ruff, supposed to be polygamous; proportion of the sexes in the; pugnacity of the; double moult in; duration of dances of; attraction of the, to bright objects.
Ruminants, male, disappearance of canine teeth in; generally polygamous; suborbital pits of; sexual differences of colour in.
Rupicola crocea, display of plumage by the male.
Ruppell, on canine teeth in deer and antelopes.
Russia, numerical proportion of male and female births in.
Ruticilla.
Rutimeyer, Prof., on the physiognomy of the apes; on tusks of miocene boar; on the sexual differences of monkeys.
Rutlandshire, numerical proportion of male and female births in.
Sachs, Prof., on the behaviour of the male and female elements in fertilisation.
Sacrifices, human.
Sagittal crest, in male apes and Australians.
Sahara, fertility of mixed races in; birds of the; animal inhabitants of the.
Sailors, growth of, delayed by conditions of life; long-sighted.
Sailors and soldiers, difference in the proportions of.
St. John, Mr., on the attachment of mated birds.
St. Kilda, beards of the inhabitants of.
Salmo eriox, and Salmo umbla, colouring of the male, during the breeding season.
Salmo lycaodon.
Salmo salar.
Salmon, leaping out of fresh water; male, ready to breed before the female; proportion of the sexes in; male, pugnacity of the; male, characters of, during the breeding season; spawning of the; breeding of immature male.