82 ORALLY. . 



as even occasional visitants, coming in seasons of a peculiar 

 character, from the recurrence of which a second visit of the 

 birds might be expected. 



The straggling of birds must depend upon natural causes,, 

 as well as their periodical migrations, or their residence in. 

 the same spot ; but the law or succession of those causes, i.i 

 a matter of wider and more difficult observation ; and the 

 difficulty is increased when the straggling is much in longi- 

 tude, as is the case with most of the coulter-billed grallae. 



Of the remaining and far more numerous group of British 

 birds formed by this division, the bills are so different that 

 no common name can be accurately or very usefully applied 

 to them, so that any attempt to subdivide the order from the 

 form of the bill is of comparatively little use in facilitating 

 the study of British birds. 



The wings and tails do not form good means of sub- 

 division ; as, though the whole of the order are well-winged 

 birds, they do not use these organs of flight in the chase of 

 their prey, but merely in transporting themselves from place 

 to place ; and their wings are more powerful in proportion 

 as the places in which they find their food are more widely 

 scattered, and also as the supply depends more upon the 

 season. 



Many of the order can swim, some are good swimmers, and 

 some can dive readily; but as these motions are only occa- 

 sional, they cannot well be made distinctive characters of 

 any groups more comprehensive than genera. Indeed, any 

 characters more extensive than generic ones, are of com- 

 paratively little value in the order. 



The habit in which they all agree the most, is that of find- 

 ing their food on or below the plane upon which they stand, 

 and not using their wings like the air birds, or a perch like 

 the bush and tree birds, in the immediate reach of it. It is 

 in that habit chiefly that the general character of the order 



