AN ORNITHOLOGICAL LECTURE. 91 



long necks and longer legs to encumber them. The wood- 

 pecker's progress is in a series of long undulations, opening 

 and closing the wings at every stroke. Our thistle-loving 

 goldfinch also flies this way, but the most of the Fringil- 

 lidce (finches, sparrows, etc.) have a short, jerking flight, 

 accompanied with many bobbings and flirtings. Warblers 

 and fly-catchers fly high up, smoothly and swiftly. Swal- 

 lows and night- hawks seem to be mowing the air with 

 cimitar wings, and move with surprising energy. On the 

 ground, most small birds are hoppers, like the sparrows, 

 but a few, like the robin and water-thrush, truly and grace- 

 fully walk, and the "shore-birds" are emphatically runners. 

 Among all sorts, queer movements are assumed in the love 

 season, not noticeable at other times. 



There is no part of the world where the feathered tribe 

 is not represented ; but no two quarters of the globe, and 

 scarcely any two places a hundred miles apart, have pre- 

 cisely the same sort of birds, or in similar abundance. 

 There are several reasons for this : first, the influence of 

 climate. Birds provided with the means of resisting the 

 extreme cold of northern regions would be very uncom- 

 fortable under a southern sun. The geographical distribu- 

 tion of plants has long been recognized, but it is only re- 

 cently that a like distribution of birds has been proved 



