40S BIRD ft 



fore part of the bafe of the metacarpal bones ; this laft, in a few rare inftances, ends 

 in a fpine,^/>2tf, as in the Oftrich, Screamer, fome Plovers, the Jacana, and a few of 

 the Duck tribe. 



The hinder extremities of birds confift of the Thighs, Legs, Toes, and Claws. The 

 Thighs, femora, are flefhy, and generally covered with feathers, except thofe of Buf- 

 tards, Oftriches, and the order of Waders, Grallae, which are naked on the lower half; 

 thofe of web-footed water fowls are likewife fomewhat naked towards the knees, but 

 in a lefs degree. In moft birds the thighs are fo placed as to fupport the weight of the 

 body in exact equilibrium, except in web-footed water fowls, on which, for the conve- 

 nience of fwimming, they are placed much backwards, behind the center of gravity, 

 which caufes thefe birds to walk in a conftrained manner : In the genera of Grebe, 

 Auk, Guillemot, and Penguin, the thighs are concealed within the common integu- 

 ments of the belly, fo that in walking, which they do with great difficulty, their legs 

 feem tied together ; this is called by ornithologifts Fettered legs, pedes compedes. In 

 fome birds, as in the Coot, there is a coloured circle, fometimes two, or three, near 

 the joint of the knee ; this is called the Bracelet, armilla. The Legs, tibiae, are thin, 

 lean, and tendinous ; generally naked, being feldom clothed with down or feathers, 

 and are fometimes covered with fcales ; in a few fpecies the back parts of the legs are 

 armed with fliarp horny fpurs, calcaria, efpecially in males. 



The Toes, digiti, vary in number, difpofitlon, and fome other circumftances, from 

 which the feet get feveral appellations, of confiderable ufe in diftinguifhing the orders 

 and genera of birds. In general, they may be diftinguifhed into fuch as have four toes, 

 tetradaclyli, in which, for the moft part, three of the toes ftand forwards, and one back- 

 wards ; and into three toed feet, tridaftyli, which want the hind toe : The four-toed feet 

 are fubdivided into feveral kinds according to the difpofition of the toes ; all land birds 

 that perch on trees have three toes turned forwards, and one backwards, which may be 

 termed Perching feet, infidentes, though ornithologifts have ufually called them Pedes 

 ambulatorii, or Walking feet ; in fome the toes are connected, two together, but with- 

 out any interpofed membrane, as in the King-fifher and others, in which cafe they are 

 termed Walking feet, grejforii ; when two of the toes are turned forwards, and two 

 backwards, they are called Climbing feet, fcanforii, as in Parrots, Woodpeckers, and 

 other birds which climb much ; Parrots have the power of occafionally turning one of 

 thefe back toes forwards ; and Owls, whofe feet are of the perching kind, can at plea- 

 fure render them climbers by turning back one of the fore toes : In fome birds, as in 

 the White-backed Coly, the Swift, and fome others, all the four toes ftand forwards, 



when 



