VI PICIDAE 457 
phus has some dozen fairly uniform green members, relieved by a 
white, bluish, or black throat. The rump may be crimson or 
rufous, the rectrices tipped with chestnut, and the bill a mixture 
of red, black, yellow, or horn-colour, usually with a white line at 
the base. The range is from Mexico to Guiana and Bolivia. 
Fam. XVIII. Picidae.—The Woodpeckers form a very large 
Family of scansorial birds with zygodactylous feet, which is so 
natural that Huxley raised it to higher rank as Celeomorphae, 
while Parker separated it still further as Sawrognathae. The two 
Sub-families are (1) Picinae, or Woodpeckers, and (2) Lynginae, 
or Wrynecks. 
Sub-fam. 1. Picinae-—The chief external peculiarities of this 
section he in the form of the large head, the neck, and the tail- 
feathers. The neck is often much compressed, with exceedingly 
powerful muscles, which, coupled with the strong, wedge-shaped. 
bill, enable the bird to operate with ease and celerity upon the 
boles and limbs of trees, whence it procures much of its food, and 
where it excavates a deep hole for the reception of its eggs. The 
shafts of the twelve tail-feathers, cf which the outer pair are very 
small, are in the majority of cases stiff and spiny, and therefore 
well adapted to keep the body close to the bark while climbing ; 
parallel cases being those of the Tree-Creeper (Certhia) and the Den- 
drocolaptinae. The shape of the tail is rounded or cuneate; the wings 
are moderate and not very much pointed, with ten primaries and 
from ten to thirteen secondaries. The metatarsus is short, with a 
single row of anterior scutes; the claws are large, sharp, and curved." 
The tongue is excessively long and “ worm-like,” with horny, 
barbed tip, and is capable of marvellous protrusion owing to the 
elongated “horns” of the hyoid apparatus, which in some forms 
curve round the skull and have their origin near the base of the 
bill. Facility is thus secured for searching narrow cracks or deep 
hollows for insects, while the secretion from the large salivary 
glands secures the adhesion of the objects aimed at. The furcula 
is U-shaped, the syrinx tracheo-bronchial, the after-shaft rudi- 
mentary, while neither adults nor young have down at any stage. 
The prevailing colours are green, yellow, black, and white, in 
various combinations, with spots and bars; brilliant scarlet being 
commonly present on the crown and frequently also on the back 
1 The hallux is often aborted, producing a tridactylous, instead of a zygodac- 
tylous, foot (cf. p. 10). 
