KUNXING BIKDS. 445 



Tlie Pigeons ( Cohcmba), like the preceding, have the beak vaulted, 

 the nostrils pierced iu a membrauoiis space, and covered with a carti- 

 laginous scale, that causes a considerable prominence at the base 

 of the beak. These buxls fly well, the males attach themselves 

 strictly to a single female, with whom they live, roosting upon trees 

 or in the clefts of rocks, — they lay few eggs, but at intervals 

 frecjueutly repeated. The male assists the female in the work of 

 incubation. They feed their young brood with grain previously 

 softened in their own craw. 



Ordek of Running Birds. 



cuesokes.* 



The principal characteristi(3 of these birds consists 

 in the undeveloped condition of their wings, which 

 are quite dispropoi;tioned to the size of the bbdy, and 

 completely incapable of flight. In some cases, these 

 rudinientary wings are but imperfectly furnished 

 with feathers, in others they are fully plumed, but 

 even then seem only to be used after the manner 

 of sails, to catch the wind and thus assist in run- 

 ning. They run witli extraordinary swiftness, and 

 hence the name Cursores, or Runners, is applied to 

 them with great propriety. The living species 

 form two families, of one of which the Ostrich, 

 and of the other, the Apteryx, is the type. 



The Ostriches (Strutliionidai) are remarkable for the great size and 

 strength of their legs; the shortness of their wings is such that 

 they are Cjuite imadapted fur flight. 



'i'lie True Ostriches {Strutldo), however, still have thinr wings 

 covered witli loose and floating plumes of sufficient lengtli to aftbrd 

 tliom considerable assistance in nmning. Two species only are 

 known. The African Ostrich [Strutldo camelus), and the American 

 Ostrich {Strulhio Bhcea). 



The African Ostrich has only two toes upon each foot ; and 

 the outermost of the two, which is but half the length of the inner 

 one, is without a claw. These birds are very numerous in the sandy 

 deserts of Arabia and of the interior of Africa ; they attani the height 

 (jf seven or eiglit feet, live in large flocks, and lay eggs that weigli 

 nearly three pounds apiece : in intertropical regions these eggs are 

 siinplY buried in the sand, but beyond the tropics the female sits 



Cursor, a runiter, from cmro, to 'im. 



