122 THE FEATHERED TRICES. 



And, then, wlio is not struck by the huge head of the owl ? That is the seat of organs 

 specially demanding our admiration. There is an ear of wondrous mechanism ; the audi- 

 tory cavities within the skull are prodigiously enlarged, and the external orifice is propor- 

 tionate, concealed between two extensive and membraneous valves, from the edges of which 

 proceed the feathers which form the outer view of the disc wliich encircles the face. The 

 leaves of the double valve are capable of being throivn apart, so as to give the freest 

 entrance to every slight vibration of the air, and then to concentrate it ; and the effect 

 is increased by cavities connected with the internal mechanism so widely difiiised, that the 

 owl hears mth the greatest distinctness the faintest noise, as the cry of a mouse, or even 

 its rustle among the straw. 



No less remarkable is the organ of sight than that of hearing. The eyes of the owl 

 are expressly adapted to the subdued light of evening and night ; the pupils being cap- 

 able of great dilatation. At that season the eyes of a cat may be seen to glare with an 

 unwonted brightness, and in this there is a i-esemblance to those of the owl. But the 

 latter are inferior m power to the former ; and hence the provision of the nictitating 

 membrane, to which allusion has already been made. During the day, the nocturnal 

 hunter remains in his retreat, with half-closed eyes, the membraneous cm-tam bemg 

 di-awn over them ; but when the shades of evening are gathering, the membranes are 

 folded up at the comer angles within the socket, and the eyes, fuUy opened, are perfectly 

 ready for the chase. 



The head of the owl, enlarged for this remarkable provision, has a globular contour 

 from the peculiar arrangement of the plumage which covers it. The top of it is gar- 

 nished, in many species, with two elongated tufts, commonly called ears, from their 

 appearance, and capable of bemg erected and depressed. And, then, how fuU, soft, and 

 downy is the whole plumage ! Other bii-ds produce sounds by then- movements. Who 

 has not heard the whisth:ig rush of the fleet-winged pigeon, or the whirrmg of the 

 pheasant rismg in the air ? But those who have observed the owl skimmuig round the 

 fai-m-yard, or along the hedge-row, are aware that it is pecuUarly buoyant and noiseless ; 

 and this is owing to the plumage, so loose and soft, and yielding instantly to any breath. 



