PEDIGREES AND FAMILY TIES. 223 



Taking the ostrich-tribe as our starting-point, 

 and as the most ancient forms of the second 

 division we pass on by means of the tinamous, 

 which serve as a connecting link, to the game- 

 birds. 



From the game-birds we pass to the ducks and 

 geese and their kindred, through the curious aber- 

 rant forms Palamedea and Chaiina — p. 214. 



The stork-tribe follow next, including the 

 gannet and cormorant-like birds. We pass 

 from these to the hawk-tribe, and thence to 

 the crane-tribe, with the rails, plovers and 

 pigeons. 



In the neighbourhood of the stork-tribe come 

 the penguins, the petrels and the divers. 



Turning to the vicinity of the game-birds again, 

 we come to the opisthocomus, and pass from this 

 ultimately to the highest groups of all. On the 

 way we encounter the touracous and cuckoos, 

 hornbills and hoopoes, rollers, and so on through 

 trogons, rollers, and many more, to the wood- 

 peckers, and from thence to the passeres, the 

 highest group of all. 



The gap-winged parrots, owls, night-jars and 

 swifts, and the kingfishers, are more closely related 

 one to another, than to the non-gap-winged forms 

 already referred to. 



On account of the remarkable gap-winged con- 

 dition of these birds it is probable that they must 

 be regarded as branching off low down the avian 

 tree from the galline stock, possibly from an ally 

 of the megapodes (p. 146), just as the kindred 

 forms do from that other aberrant game-bird, 

 the opisthocomus. They bear no such direct 



