334 



NATURAL HISTORY. 



eA. 



Ji.br. 



THE FIFTH FAMILY OF THE ZYGODACTYLE PICARIAN BIRDS. THE WOODPECKERS (Pieidte). 



These are perhaps the most typical of all the yoke-footed or climbing birds, as they are most 

 expert climbers, being aided in the latter operation not only by their long toes, which are arranged 

 as usual in this order in pairs, but by their stiffened tail, which enables them to climb with great 

 rapidity up the perpendicular trunks of trees. If they wish to descend a little 

 way they do not turn and come down head-foremost, as a Nuthatch would do, 

 but they let themselves down by a few jerks, still keeping an oblique position, 

 with the tail downwards. The bill in almost every member of the family is 

 wedge-shaped, and very powerful, and with this organ a Woodpecker taps vigorously 

 at the bark, which he sometimes also prises off to get at the grubs or insects under- 

 neath. These latter, as they endeavour to escape, have little chance against the 

 intruder, who, in addition to the stout bill which discloses their place of conceal- 

 ment, possesses a peculiar tongue, which is capable of being protruded to a long 

 distance, is furnished with minute barbs at the end, and is covered with a glutinous 

 fluid from which the insects are unable to free themselves. The Woodpeckers 

 nearly all procure their food in the above manner, but occasionally frequent the 

 ground, and the Green Woodpecker (Gecinus * viridis) commits great ravages 

 among ant-hills. The resting-place is generally a hole excavated by the bird itself 

 in a hollow tree, and the eggs are white. Among ths most aberrant of the 

 Woodpecker family are the Wrynecks (lyuxty, of which one species is well known 

 in England under the name of the " Cuckoo's mate." The Wrynecks are all birds of 

 beautiful mottled plumage, and do not have a stiffened tail like a true Woodpecker. 

 They are found in Europe, 

 i n India, North-Eastern and 

 Southern Africa. Wood- 



P 6ckerS > OI1 the tll6r liand > 



. 



are extremely plentiful in the 

 J?.y^!MBl New World, and are distri- 



Uro-byal; (<-M e.br) to- .. _ 



getiier form the thyro- buted all over Atrica, xLurope, 



Jbyal- 



and Asia, but are not found in 

 the Australian region, no Woodpecker occurring 

 beyond the Island of Celebes in the Moluccas. 



One great peculiarity in the anatomy of 

 the Woodpeckers is the structure of the tongue, 

 and its relation to the hyoid bone and its horns, 

 or cornua. (For a description of this part in 

 the Mammalia, see Vol. I., p. 168.) In Birds 

 the hyoid bone is a much more complex structure 

 than in the Mammalia. Besides forming the 

 basis of the otherwise mainly muscular substance 

 of the tongue, it is continued backwards in most 

 birds as a double chain of bones, each pair of 

 which bears a separate name significant of 

 importance ; and the whole is apparently quite 

 distinct from the skull above and from the 



larynx below. Its composition in the common fowl is best rendered intelligible by reference to 

 the accompanying woodcut (Fig. 1). It represents the entire hyoid apparatus divested of all muscular 

 and other surrounding tissues. The upper part of the figure is that nearest to the tip of the tongue, 

 and the references to the lettering become clear in the course of the subsequent description. 



Another woodcut (Fig. 2) shows a side view of a dissection of the head of the common Green Wood- 



* yj, earth, and <ave'o), I shake ; viridis, green. 



f The classical Greek name, from its double note sounding like the exclamation W, hence the verb Wfw, I cry out. 



Fig 1. "HYOID" 

 BONE OF ADULT 



S 

 A. 



cerato-hyais: 



Fig. 2. SIDE VIEW OF DISSECTION OF 

 HEAD OF COMMON GREEN WOODPECKER. 



(Half natural size. After Macgillivray.) 



^ os it 11 , la.u.i IVI^UL otii LYIUJ \jiifi ma , V"*' "*' * W* >- "*" i '""V- 



tr) Trachea; (r.m.) Retractor Muscles of Tongue wound round Trachea. 



