ACCIPITRES. 1G3 



again excepted] pursue other Birds ; their flight accordingly is mostly powerful. The 

 greater number still retain a slight web betwixt their external toes. 



The Passerine Birds comprise many more species than all the other families ; but 

 their organization presents so many analogies that they cannot be separated, although 

 they vary very much in size and strength. Their two external toes are joined at the 

 base, and sometimes higher. 



Finally, the name of Climbers is applied to those Birds in which the external toe is 

 directed backwards like the thumb, because the greater number of them [some of them] 

 avail themselves of a conformation so favourable for a vertical position, to climb along 

 the trunks of trees.* [As constituted upon this single character, the present group is 

 a most unnatural one, excluding genera that in every other respect belong to it, and 

 including the Parrots, which differ widely from the rest in every other detail of their 

 conformation. Besides the Parrots, also, which are the only true climbers among 

 Birds, (if we except perhaps the Colics,) the Woodpecker and Barbet groups comprise 

 all the yoke-footed species which ascend the trunks of trees, the latter only being 

 enabled to descend them ; and corresponding genera to these occur among the Passerine 

 Birds, as the Creepers and their allies — to the Woodpeckers, and the Nuthatches — to 

 the Barbets. The Trogons moreover, as stated at p. 1.56, are yoke-footed on a different 

 principle from the rest. We have no hesitation in placing the Parrots at the head of 

 the whole series of the class of Birds.] 



Each of these orders subdivides into families and genera, principally after the con- 

 formation of the beak. But these different groups pass into each other by almost 

 imperceptible gradations, insomuch that there is no other class in which the genera 

 and subgenera arc so difficult of limitation. 



THE FIRST ORDER OF BIRDS,— 



THE BIRDS OF TREY {ACCIPITRES, Lin.)— 



Are recognized by their hooked beak and talons, — powerful weajjons, with which they immo- 

 late other Birds, and even the weaker Quadrupeds and Bei)tiles. They are among Birds what 

 the Cariiivorn are among Quadrupeds. t The muscles of tlieir thighs and legs indicate the 

 force of their claws ; tlieir tarsi are rarely elongated : they liavmg all four toes ; and the claw 

 of the thunil) and that of the innermost toe are the strongest. 



They constitute two families, the Diurnal and the Nocturnal. 



The Diurnal Birds of Prey have the eyes directed sideways; a membrane, termed the 

 cere [as in the Parrots], covering the base of the beak, in which the nostrils are pierced; three 

 toes before [the outer m the Osprey genus reversible], and one behind, unfeathered, the two 

 exterior almost ahiays connected at base by a short mendirane ; the jilumage close, the quills 

 strong, and Hight powerful. [Tliey have constantly a large craw (fig. 71) or dilatation of the 

 £rullct] ; their stomach is almost wliolly membranous ; their intestines [save in the Osprey 

 genus] but little extended, and furnished with minute cccea. Tlie sternum (fig. 72) is large 

 and completelj' ossified, [or with only a jiosterior foramen left, in most of the genera], in 

 order to give more extended attachment to the muscles of the wing ; and their fourchette 



ji'.ls, Irivc assenCu'I to tliiji sujiprussion. 



lus I'lirrotfi may bu compared tu tlie Qnndrujnana, 



