494 



THE REASON WHY IN NATURAL HISTORY. 



Because long legs would greatly impede their 

 motions in the water, by becoming repeatedly 

 entangled in the weeds, and by striking against 

 the bottom. Waders, however, require long legs 

 because they have to move about through the 

 tall vegetation of marshy borders. 



56. Why have the feet of the heron, cormorant, 

 etc. , deep rough notches upon their under surface ? 



Because, as those birds live by catching fish, 

 they are enabled by the notches in their feet, to 

 hold the slippery creatures upon which they feed. 



57. Why do woodpeckers " tap " at old trees ? 

 Because by boring through the decayed wood, 



with the sharp and hard bills with which they 

 are provided, they get at the haunts of the insects 

 upon which they feed. 



58. Why are woodpeckers 1 tongues about three 

 times longer than their bills t 



Because, if their bills were long, they would 

 not bore the trees so efficiently ; and when the 

 trees are bored, and the insects alarmed, they 

 endeavor to retreat into the hollows of the wood; 

 but the long thin tongue of the woodpecker fixes 

 them on its sharp horny point, and draws them 

 into the mouth of the bird. 



59. Why have birds gizzards ? 



Because, having no teeth, the tough and 

 fibrous gizzards are employed to grind the food 

 preparatory to digestion. 



60. Why are small particles of sand, stone, etc., 

 found in the gizzards of birds ? 



Because, by the presence of those rough parti- 

 cles, which become embedded in the substance 

 of the gizzard, the food of the bird is more effect- 

 ively ground. 



When our fowls are abundantly supplied with meat, they 

 soon fil/ their craw, but it does not immediately pass thence 

 into the gizzard; it always enters in small quantities, in 

 proportion to the progress of trituration; in like manner, as 



in a mill, a receiver is fixed above the two large stones 

 which serve for grinding the corn, which receiver, although 

 the corn be put into it by bushels, allows the grain to drib- 

 ble only in small quantities into the central hole in the upper 

 mill-stone. 



6 1 . Why have birds of prey no gizzards ? 

 Because their food does not require to be 



ground prior to digestion, as does the food of 

 grain-eating birds. 



62. Why has the pelican a large pouch under its 

 bill ? 



Because it subsists upon fish, generally of the 

 smaller kind, and uses its pouch as a net for 

 catching them ; the pouch also serves as a 

 paunch, in which the fish are stored, until the 

 bird ceases from the exertion of fishing, and 

 takes its meal at leisure. 



In their wild state they hover and wheel over the surface 

 of the water watching the shoals of fish beneath, and sud- 

 denly sweeping down, bury themselves in the foaming 

 waves; rising immediately from the water by their own 

 buoyancy, up they soar, the pouch laden with the fish 

 scooped up during their momentary submersion. The 

 number of fish the pouch of this species will contain may 

 be easily imagined when we state that it is so dilatable as to 

 be capable of containing two gallons of water; yet the bin! 

 has the power of contracting this membraneous expansion, 

 by wrinkling it up under the lower mandible, until it is 

 scarcely to be seen. In shallow inlets, which the pelicans 

 often frequent, it nets its prey with great adroitness. 



The pelican chooses remote and solitary islands, isolated 

 rocks in the sea, the borders of lakes and rivers, as its 

 breeding-place. The nest, placed on the ground, is made 

 of coarse grasses, and the eggs, which are white, are two or 

 three in number. While the female is incubating, the mala 

 brings fish to her in his pouch, and the young, when 

 hatched, are assiduously attended by the parents, who feed 

 them by pressing the pouch against the breast, so as to 

 transfer the fish from the former into the throats of the 

 young. The action has doubtless given origin to the old 

 fable of the pelican feeding its young with blood drawn 

 jrom its own breast. 



63. Why does the lower -bill of the sea-crow pro- 

 ject beyond the upper one ? 



Because the bird obtains his food by skimming 

 along the water into which he dips his bill, and 

 lifts his food out. 



64. Why do the mandibles of the cross-bill over- 

 lap each other ? 



Because the bird requires a peculiar bill, to 

 enable it to split seeds into halves, and to tear 

 the open cones of the fir-tree. 



INSECTS. 



65. Why has the spider the power of spinning 

 a web t 



Because, as it lives upon flies, but is deficient 

 of the power of flying in pursuit of them, it has 

 been endowed with an instinct to spread a snare 



to entrap them, and with the most wonderful 

 machinery to give that instinct effect. 



There are few things better suited to remove the disgust 

 into which young people are betrayed on the view of some 

 natural objects, than this of the spider. They will find that 

 the most despised creature Tiay becom* a subject of admira- 



