INDEX 



845 



Odonata, 336. 



Odonescis potatoria, sexual difference 



of color in, 412. 

 Odor, correlation of, with color of akin, 



261-262; emitted by snalses in the 



breeding-season, 45^; o£ mammals, 



683. 

 CEcanthus nivalis, difEerence of color in 



the sexes of, 380. 



pellucidua, 380. 



Ogle, Dr. W., relation between color 



and power of smell, 36. 

 Oidemia, 634. 

 Olivier, on sounds produced by Pimelia 



striata, 400. 

 Omaloplia brunnea, stridulation of, 397. 

 Onitia furcifer, processes of anterior 



femora of the male, and on the head 



and thorax of tiie female, 390. 

 Onthophagus, 389. 



rangifer, sexual differences of, 



388 ; variation in the horns of the 

 male, 389. 



Ophidia, sexual difEerences of, 456. 



Ophidium, 451. 



Opossum, wide range of, in America, 

 226. 



Optic nerve, atrophy of the, caused by 

 destruction of the eye, 53. 



Orang-outang, 722; Bisehoff on the 

 agreement of the brain of the, with 

 that of man, 22; adult age of the, 

 25 ; ears of the, 32 ; vermiform ap- 

 pendage of, 40; hands of the, 75; 

 absence of mastoid processes in the, 

 78-79; platforms built by the, 96; 

 alarmed at the sight of a turtle, 

 103-104; using a stick as a lever, 

 11 5 ; covering itself with straw, 115 ; 

 using missiles, 115 ; using the leaves 

 of the Pandaniis as a night cover- 

 ing, 117 ; direction of the hair on 

 the arms of the, 202-203; its aber- 

 rant characters, 206; supposed evo- 

 lution of the, 236; voice of the, 681 ; 

 monogamous habits of the, 759; 

 male, beard of the, 686. 



Oranges, wild, treatment of, by Amer- 

 ican monkeys, 75. 



Orange-tip butterfly, 403, 408. 



Orohestia Darwinii, dimorphism of 

 males of, 354. 



— Tueuratinga, limbs of, 353, 358. 

 Ordeal, trial by, 133. 



Oreas canna, colors of, 692. 



Oreas Derbianus, colors of, 692, 702. 



Organs, prehensile, 277; utilized for 

 new purposes, 735. 



Organic scale, von Baer's definition of 

 progress in, 219. 



Orioles, nidiflcation of, 584. 



Oriolus, species of, breeding in imma- 

 ture plumage, 625. 



melanocephalus, coloration of the 



sexes in, 594. 



Ornaments, prevalence of similar, 238; 

 of male birds, 476; fondness of sav-. 

 ages for, 739. 



Ornamental characters, equal transmis- 

 sion of, to both sexes, in mammals, 

 700; of monkeys, 707. 



Ornilhoptera croeaua, 331. 



Ornithorhynchus, 209 ; reptilian ten- 

 dency of, 212; spur of the male, 

 649. 



Orocetes erythrogastra, young of, 628. 



Orrony, Grotto of, and the humeri of 

 the Bronze period, 41. 



Orsodacna atra, difEerence of color in 

 the sexes of, 386. 



Orthoptera, 372 ; metamorphosis of, 

 311; stridulating apparatus of, 372, 

 378; colors of, 380; rudimentary 

 stridulating organs in female, 378; 

 stridulation of the, and Homoptera, 

 discussed, 378. 



Ortygomis gularis, pugnacity of the 

 male, 472. 



Oryctes, stridulation of, 397 ; sexual 

 difEerences in the stridulant organs 

 of, 399, 400. 



Oryx leucoryx, use of the horns of, 

 667, 668. 



Osphranter rufus, sexual difEerence in 

 the color of, 689. 



Ostrich, African, sexes and incubation 

 of the, 617. 



Ostriches, stripes of young, 599. 



Otaria jubata, mane of the male, 672. 



nigrescens, difEerence in the color- 

 ation of the sexes of, 691. 



Otis bengalensis, love-antics of the 

 male, 493. 



tarda, throat-pouch of the male, 



483; polygamous, 290. 



Ouzel, ring-, colors and nidiflcation of 

 the, 587. 



, water-, colors and nidiflcation of 



the, 587. 



Ovibos mbachatus, horns of, 653. 



