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.
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