STERNUM OF THE GOAT-SUCKER. 337 



their styles of flight. They are both tree or copse 

 birds, and they never take very long flights when 

 they are in search of their food ; and the sternum, 

 from the deep notches in its posterior edge, is not 

 nearly so well adapted for bearing up the body upon 



Goat-sucker. 



long flight as that of the swifts and swallows. Here 

 we may remark, by the way, though the assumption 

 which suggests the remark is now exploded, that 

 there is nothing in the sternum of the cuckoo to pre- 

 vent that bird from setting upon and hatching eggs 

 in the same manner as other birds do. In their ordi- 

 nary habit these birds neither fly fast nor take long 

 flights ; but the ordinary habit of a bird while resident 

 in one locality is not a certain proof to the full extent 

 of what it can do. The cuckoo flies only from copse 

 to copse, or from one tree in the hedge-row to another ; 

 and when feeding its motions are even more limited. 

 But both are very light birds in proportion to their 

 size, and their plumage is soft and loose, so that they 

 float in the air with very easy though not rapid wing. 

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