548 



NATURAL HISTORY. 



aid in holding them in position, while their chisel-like beak is boring the 

 holes in the bark. The question whether their habits are to be regarded 

 for good or for evil to the farmer has often been raised, but it is hard to- 

 say in which direction the balance lies. They do good by destroying inju- 

 rious insects ; but, on the other hand, there can be no doubt but that their 

 punctures affect the tree, especially at the time when the sap is flowing.. 

 Some are even accused of eating the soft inner bark. 



There is one structural feature in the woodpeckers to which attention 

 should be directed. In all birds (and in mammals as well) the tongue is. 

 attached to a little Y-shaped bone, called the hyoid bone, because some old 



anatomist with a very vivid 

 imagination imagined that the 

 same bone in man resembled 

 the Greek letter Y. Now the 

 woodpeckers have to get their 

 food from the holes which, 

 they make in the bark ; and 

 when one of these holes strikes 

 the burrow of some insect, in 

 goes the tongue, probing it to- 

 its depth, and bringing out the 

 grub. To do this it is neces- 

 sary that the tongue be very 

 extensile, and this is rendered 

 possible by having the hyoid 

 bone very long, and running, 

 as shown in the cut, around the base of the skull and over its crown. The 

 tongue itself is furnished with barbs like those of a fish-hook, thus rendering 

 it possible to draw out the grub speared by it. 



The trogons, which live in the tropical parts of both continents, are 

 beautiful birds, the form figured (the quesal) being the handsomest of all. 

 The male is by far the most beautiful of the two: it is of a rich bronze- 

 green, which no humming-bird can excel, while the true tail — not the 

 long tail-coverts — is black and white, and the belly is a rich vermilion 

 or crimson. Is it any wonder that Guatemalans have adopted it as their 

 national emblem, and placed its portrait on their postage stamps? Its 

 body is no larger than that of a crow, but the two longest feathers may 

 hang down for nearly three feet. One would think that such long orna- 

 ments would incommode him in his flight through the forest: not so; 

 he flies rapid and straight, his long banners streaming behind. It feeds 

 almost solely upon fruit, and this it takes in a peculiar way. It does not 



Fig. 450. — Skulls of woodpeckers, from above and from the 

 side, showing the tongue and the hyoid bones curving around 

 the base of the skull and passing above into the nostril (above) 

 and around the orbit (below). 



