THE CUCKOOS. 323 



form the palate below. But if the skull of this same bird had been carefully examined in an earlier 

 stage of its existence, it would have been found that the bones were at first distinctly separate at 

 the three points here indicated, and were merely connected by a soft membranous substance. In many 

 birds this "inter-osseous" membrane connecting the bones of the upper mandible with the skull 

 proper never becomes true bone at all, but remains throughout life more or less soft and flexible. 

 And by this means a sort of elastic joint is established, conferring upon the beak a certain range 

 of up and down motion. 



Now in Parrots, more conspicuously than in any other birds, each of these joints, not alone that 

 of the beak with the forehead, is converted into a true hinge-like articulation, so that the upper 

 jaw can be raised to a very considerable extent; and to effect 

 this motion the muscles of the palate are developed into a some- 

 what complex apparatus. 



If the figure be examined, the actual relations of the bones 

 can be readily made out. At a is seen the line where the bill 

 is articulated to the frontal bones. At b is the joint which the 

 bill makes with the long jugal bone (j). And at c is its articula- 

 tion with the palatine bone (pi). 



But it is not this mobility of the upper mandible alone that 

 gives the characteristic aspect to the Parrot's face. There are 

 several other points in which Parrots agree, with a wonderful 

 uniformity, among themselves, and differ from most other birds. Besides the absence of certain impor- 

 tant processes, called " basi-pterygoid," the ploughshare-like bone, or "vomer," is altogether wanting. 

 The maxillo-palatines are veiy largely developed and spongy ; they unite with one another in the 

 middle line, and with the thick wall of bone into which the septum iiasi is in Parrots strongly 

 ossified, and thus fill up almost the whole base of the beak. The long palatine bones proper are 

 remarkably flattened from side to side for most of their length ; their hinder edges are more or 

 less notched, and quite free from any bony attachment ; and they are iinited at about the hinder 

 third of their length by a plate-like extension from each. The scoop-like lower mandible, with 

 its tip that seems to have been cut off " square," to be out of the way of the strongly-hooked upper 

 jaw, is too familiar to call for any particular description. 



THE SECOND ORDER. PICARIAN BIRDS. SUB-ORDER I. ZYGODACTYL^E. 



CHAPTER VIII. 



CUCKOOS HONEY GUIDES PLAINTAIN-EATERS WOODPECKERS TOUCANS BARBETS. 



THE CUCKOOS THE BUSH CUCKOOS THE LARK-HEELED CUCKOOS, OR COUCALS THE COMMON CUCKOO Its Cha- 

 racteristicsMrs. Blackburn's Account of a Young Cuckoo Ejecting a Tenant Breeding Habits The Eggs The 

 Call-notes of Male and Female -Food Its Winter Home Its Appearance and Plumage THE HONEY GUIDES 

 Kirk's Account of their Habits Mrs. Barber's Refutation of a Calumny against the Bird THE PLANTAIN- 

 EATERS THE WHITE-CRESTED PLAINTAIN-EATER THE GREY PLANTAIN-EATER THE COLIES THE WHITE- BACKED 

 COLY THE WOODPECKERS How they Climb and Descend Trees Their Bill-Do they Damage Sound Trees? 

 THE WRYNECKS THE YAFFLE THE RED-HEADED WOODPECKER -- THE SPOTTED WOODPECKER THE TOUCANS 

 Mr. Gould's Account of their Habits Mr. Waterton's Account The Enormous Bill Azara's Description of the 

 Bird Mr. Bates' History of a Tame Toucan THE BARBETS Messrs. Marshall's Account of the Family Mr. 

 Layard on their Habits. 



THE SECOND ORDER OF ZYGODACTYLE PICARTAN BIRDS. THE CUCKOOS 

 WITHIN the limits of this family are comprised birds of very different habits and of very different 

 structure, some being inhabitants of the ground and of the thick bush, whilst others are lovers of 

 the open, and are birds of very strong flight. Without being able to climb up the trunks of trees, 



