568 BRITISH BIRDS. 



Family GRUID^E, or CRANES. 



The Cranes are a very small and well-defined family, but great difference 

 of opinion exists as to their afiinities. Fortes supposed them to be nearest 

 related to" the Ibises and the Plovers, but Sclater places them in the same 

 order as the Bustards. The Cranes have no notch in the posterior margin 

 of the sternum. In the modification of their cranial bones, in their ptery- 

 losis, myology, and in their digestive organs they appear to be nearest 

 allied to the Bustards and Rails. 



There can be little doubt that the Cranes moult twice in the year, early 

 in autumn and in spring. Cranes shot on the autumn migration are said 

 to be in perfect plumage ; and Naumann says that they sometimes arrive 

 at their breeding-places before the spring moult is quite complete. 



The Cranes somewhat resemble in their external characters the Herons 

 and the Storks, but may be distinguished from both by their much shorter 

 bill, which resembles in some respects that of the Plovers. The wings 

 are long, and the innermost secondaries are lengthened and pendent. The 

 tail is short and even, and composed of twelve feathers. The hind toe is 

 small and somewhat elevated. 



The young of the Cranes, like those of the Rails and the Bustards, are 

 covered with down when they are hatched, and they are able to run shortly 

 afterwards. 



It is supposed that there are only 16 species of Cranes, which are dis- 

 tributed over all the large continents of the world, but are absent from the 

 Arctic and Neotropical Regions and from all the smaller islands. Three 

 species of Crane are European, two of which are said occasionally to visit 

 our islands. 



Genus GEUS. 



The Cranes were associated by Brisson with the Storks, and by Linnaeus 

 with the Herons ; but in 1793 Bechstein established the genus Grus for 

 their reception in his ' Naturgeschichte Deutschlands ' (iii. p. 60), and the 

 Common Crane, being the Ardea grus of Linnseus, became of necessity 

 the type. 



The true Cranes have been separated from the Crested Cranes in con- 

 sequence of the absence of the bristly occipital crest, and on account of 



