624 MANUAL OF ZOOLOGY. 



" The Perchers in general have the females smaller and less 

 brilliantly coloured than the males ; they always live in pairs, 

 build in trees, and display the greatest art in the construction 

 of their nests. The young are excluded in a blind and naked 

 state, and wholly dependent for subsistence during a certain 

 period on parental care. The brain arrives in this order at its 

 greatest proportionate size ; the organ of voice here attains its 

 greatest complexity, and all the characteristics of the bird, as 

 power of flight, melody of voice, and beauty of plumage, are 

 enjoyed in the highest perfection by one or other of the groups 

 of this extensive and varied order." 



The structure of the feet, then, gives the definition of the 

 order, but the minor subdivisions are founded on the nature of 

 the beak ; this organ varying in form according to the nature 

 of the food, " which may be small or young birds, carrion, in- 

 sects, fruit, seeds, vegetable juices, or of a mixed kind" (Owen). 



In accordance with the form of the beak, the Insessores have 

 been divided into four great sections or sub-orders, known as 

 the Conirostres^ Dentirostres, Tenuirostres, and Fissirostres. 



Sub-order i. Conirostres. In this section of the Insessores 

 the beak is strong and on the whole conical, broad at the base 

 and tapering with considerable rapidity to the apex (fig. 345, 

 D). The upper mandible is not markedly toothed at its lower 

 margin. Good examples of the conirostral type of beak are 

 to be found in the common Sparrow, Hawfinch, or Bullfinch. 

 The greater number of the Conirostres are omnivorous; the 

 remainder are granivorous, or feed on seeds and grains. The 

 sub-order includes the families of the Horn-bills (Bncerotidcc), 

 the Starlings (Sturnidce), the Crows (Corvida), the Cross-bills 

 (Loxiadg), and the Finches and Larks (FrtngiUidct). 



In the Horn-bills the conirostral shape of the beak is masked, 

 partly by its being of very great size, and partly by the fact that 

 above the upper mandible is placed a hollow appendage like a 

 kind of helmet. Both the beak and the appendage above it 

 are rendered light by the presence of numerous air-cells. The 

 Horn-bills are exclusively confined to the warm countries of 

 the eastern hemisphere, and are the largest of all the Insesso- 

 rial birds, sometimes attaining the size of a goose ; and they 

 must be regarded as only provisionally placed in this order. 

 They live on fruits, and make their nests in the holes of trees. 

 The best-known species is the Rhinoceros Bird (Buceros rhino- 

 ceros) of India and the Indian Archipelago. 



The family of the Corvidce, or Crows, is an extremely exten- 

 sive one, and includes a large number of very dissimilar-look- 



