258 ANATOISIY OF VERTEBRATES. 



hive, open at the bottom, which is crossed by a perch of strong 

 woven material, upon which he sits, sheltered from the tropical 

 sun or storm by the dome above, which is suspended to a branch 

 near that to which is attached the nest of the female, whom he 

 solaces durinej her confinement with his sono;. 



Certain conirostral Cantores still practise in the undisturbed 

 wilds of Australia the formation of marriage-bowers distinct from 

 the later-formed nesting-place.^ The Satin Bower-Bird {Ptilono- 

 rhynchus holosericeus), and the Pink-necked Bowser-Bird (CA/«- 

 mydera maculata), are remarkable for their construction on the 

 ground of avenues, over-arched by long twigs or grass-stems, the 

 entry and exit of which are adorned by pearly shells, bright- 

 coloured feathers, bleached bones, and other decorative materials, 

 which are brought in profusion by the male, and variously ar- 

 ranged to attract, as it would seem, the female by the show of a 

 handsome establishment. For receiving and incubating her eggs 

 the female builds a nest, like that of the Magpie, in the conceal- 

 ment of a tree.^ 



Most birds, on reaching maturity, show external sexual cha- 

 racters. In Diurnal Raptores the female is larger than the male ; 

 in Gallinacece and most other polygamous birds, she is less. In 

 this suborder the male is most conspicuous by the richness and 

 beauty of his colours ; and a difference in this respect is the most 

 common sexual character in birds, with the frequent addition of a 

 peculiar size and shape of certain feathers, especially at the 

 breeding season, wdien, e.g., the male of Machetes pugnax becomes 

 the ' Kuff,' the female the ' Reeve.' There is a sexual difference 

 in the length of the beak in the Hook-billed Parrots (Nestor), 

 in the Apteryx, and in the singular genus of Humming-Bird 

 {Androdon, Gould), in w^hich the end of the longer bill of the 

 male is dentated. The comb and w^attles of the Cock exemj^jlify 

 sexual characters of certain cutaneous appendages : his spur 

 and that of other Gallince and PhasianidcB, including Meleagris, 

 is a w^eapon of combat, analogous to the horns of Mammalian 

 Herbivores. 



Swifts, Swallows, Doves, Crows, King-fishers, Parrots, and 

 the majority of the Waders are examples of birds in which the 

 sexes are alike. 



' Lvii. and i.viii. 



2 It is possible that the old propensity of the Magpie, Jackdaw, and some others of 

 our Conirostrals, to which the Australian Bower-Birds are allied, to pilfer glittering 

 objects, may be the remnant of a similar instinct which the increase of human popula- 

 tion has scared out of them : the conditions of cultivation reducing the birds to the 

 constructions which are essential to the continuance of the species. 



