OWLS 



though this fact has brought them no ill. Till recently they were 

 i VLT.H dod as belonging to the " Birds of Prey," which were, accordingly, 

 divided into the "diurnal " and "nocturnal," the owls forming the 

 latter. As a matter of fact, though they are indubitably "birds of 

 prey," they are, nevertheless, in no way related to the so-called 

 "diurnal" birds of prey now known as the Accipitreg, being much 

 iiioiv in -arl\ akin to the nightjars and "frog-mouths." 



The two most characteristic features that distinguish them as a 

 :roup are the strange softness of the plumage, 1 which extends even to 

 the quill feathers, which, like muffled oars, impart a peculiarly silent 

 flight a feature of the highest importance to birds which must 

 surprise an ever alert and agile prey, hunted, for the most part, during 

 the twilight hours and the curious arrangement and structure of the 

 feathers surrounding the eyes, forming the " discs " with which all of 

 us are familiar. In the upright carriage of the body, the form of the 

 beak, and feet, these birds, indeed, closely resemble the Accipttrex, but 

 this resemblance is due to " convergence " and not to descent 



As touching the structure of the foot, it must be remarked that, 

 while closely resembling the foot of an accipitrine bird, it differs in the 

 greater mobility of the toes. When perching, the toes have the 

 xygodactyle arrangement two in front and two behind ; when grasp- 

 ing prey they radiate as it were from a common centre : when the bird 

 is on the ground, however, the toes have the typical avian arrange'' 

 ment three in front and one behind. Only one or two Accipitres, 

 e.g. the osprey, are able to turn the outer toe backwards, and on this 

 account, until recently, the osprey was held to form the connecting 

 link between the Accipitres and the owls. 



The eyes of Owls are relatively larger than those of any other 

 birds, a fact explained by their nocturnal habits. In them, as in the 

 eyes of the Accipitres, the ring of bony plates, "sclerotic plates," 

 which surround the eyeball is extremely well developed, and plays an 

 important part in rapidly focussing the eye ; further, they are so lodged 



1 Which they hare with the Nightjar*. 



VOL. ii. 



