230 THE NATURAL HISTORY 



LEITER XLII 



" Omnibus animalibus reliquis certus et uniusmodi, et in suo 

 cuique genere incessus e3t : aves solae vario meatu fcruntur, et in 

 terra, et in acre." — Plin. Hist. Nat. lib. x. cap. 38. 



Seleohke, Aug. 7, 1778. 

 Dear Sir, 



A good ornithologist should be able to distinguish birds 

 by their air as well as by their colours and shape ; on the 

 ground as well as on the wing, and in the bush as well as 

 in the hand. For, though it must not be said that every 

 species of birds has a manner peculiar to itself, yet there 

 is somewhat in most genera at least, that at first sight 

 discriminates them, and enables a judicious observer to 

 pronounce upon thcin with some certainty. Put a bird 

 in motion 



..." I'A vera inccssu patuit." .... 



Thus kites and buzzards sail round in circles with 

 wings expanded and motionless ; and it is from their 

 gliding manner that the former are still called in the north 

 of England gleads, from the Saxon verb glidan to glide. 

 The kestrel, or wind-hover, has a peculiar mode of 

 hanging in the air in one place, his wings all the while 

 being briskly agitated. Hen-harriers fly low over heaths 

 or fields of corn, and beat the ground regularly like a 

 pointer or setting-dog. Owls move in a buoyant manner, 

 as if lighter than the air ; they seem to want ballast. 

 There is a peculiarity belonging to ravens that must draw 

 the attention even of the most incurious— they spend all 

 their leisure time in striking and cuffing each other on 

 the wing in a kind of playful skirmish ; and, when they 

 move from one place to another, frequently turn on their 

 backs with a loud croak, and seem to be falling to the 



