IV. VERTEBRATA: AVES, CARINAT.-E 



543 



appear like small scales. Thus the distinctions between ratite and carinate 

 birds vanish in places. 



Sub Order 1. GALLINACEA. The hen-like Ijirds are praecoccs with 

 compact bodies and well-developed wings and legs, so that they run and Hy 

 well without excelling in either direction. The feet have three toes in front, 

 usually connected by a membrane at the base (fig. 594, c) ; the first toe is behind 

 and at a higher level. Above this in the male is usually the spur, a process of 

 the tarso-metatarsus, covered with horn; scratching claws. Naked, richly 

 vascular lobes form comb and wattles which are specially large in the more 

 elegantly plumaged males. Phasl-vnid^, Phasianus, pheasants; Galhis bankiva 

 of the Sunda Islands, ancestor of domestic fowl. Meleagris* turkeys. Tetea- 

 ONID.E, Cotuniix* quail; Pcrdix* partridge; Bonasa* grouse. The incubation 

 of the Megapodes has been referred to (p. S4i)- 



Sub Order II. COLUMBIN.Ii. Pigeons are distinguished from Gallin- 

 acea: by the more slender bodies, shorter legs, free toes, and the longer wings 

 capable of prolonged flight. They are altrical; the crop produces a milky 

 secretion used in feeding the young. Columba* According to Darwin 

 domestic pigeons come from C. livia, the blue rock pigeon. Allied was the 

 dodo, Didiis ineplus, of Madagascar, exterminated in the eighteenth century. 



Sub Order III. NATATORES. The swimming birds, with webbed feet, 

 are excellent swimmers and divers. Either all four toes are connected by the 

 web (fig. 594, /), or only the three anterior toes are webbed [k), or the three toes 

 are each bordered with a swimming mem- 

 brane (h). Thus the foot structure gives 

 distinctions which forbid a closer asso- 

 ciation of the families, and this is 

 strengthened by differences of wing and 

 beak. On the other hand palatal struc- 

 tures show that here, as in the Grallatores, 

 very diverse forms are associated. 



Section I. Lamellirostres (Anseri- 

 formes), feet palmate; the beak soft- 

 skinned up to the hard tip, its margins 

 with transverse horny plates. Anas 

 hoschas* wild duck, source of domestic 

 breeds. Anser* goose (domestic derived 

 from A. ferns). Cygmis* swans. Sec- 

 tion II. TuBiNARES (Longipennes), pre- 

 daceous birds with strong beak, tubular 

 nostrils, palmate feet, and long wings . 

 capable of rapid and prolonged flight. %« 

 Diomedea, albatross; Lams'' gulls; 

 Sterna* terns. Section III. Urinatores. 

 Birds with small wings, sometimes re- 

 duced to flippers, and upright position 

 owing to position of the legs far back. 

 The Alcid^ {Alca impennis* the great auk.) Antarctic Impennes 

 (Aptenodytes — fig. 595, penguin), CoLYMBiDyE: Urinator* loons, Colymbus* 

 grebes. Section IV. Steganopodes, totipalmate feet. Pelecamis* pelicans; 

 Phalarocorax* cormorants; Phaethov* tropic birds. 



Sub Order IV. GRALLATORES. Wading birds; legs lengthened, chiefly 

 by elongation of the tarso-metatarsus, the feet semi-palmate (fig. 594, a), and 

 the feathers only on the upper parts, the lower with horny plates. Correlated 

 is the striking length of neck and beak. These features have appeared in 



Fig. 595. — Aplenodytcs patagmiica^ 

 penguin (from Brehm). 



