1047. Why have the parrots, &c., crooked and hard bills?
Because they live upon nuts, the stones of fruit, and hard seeds. The shape of the bill, therefore, enables them to hold the nut or seed firmly, and the sharp point enables them to split or remove the husks.
1048. Why can a parrot move its upper as well as its lower bill?
Because by that means it is enabled to bring the nut or seed nearer the fulcrum, or joint of the jaw. It, therefore, acquires greater power, just as with a pair of nut-crackers we obtain increased power by setting the nut near to the joint.
1049. Why have animals with long necks large throats?
Animals that graze, or feed from the ground, generally have a more powerful muscular formation of the throat than those which feed in other positions, because a greater effort is required to force the food upward, than would be needed to convey it down.
1050. Why are the bones of birds hollow?
Because they are thereby rendered lighter, and do not interfere with the flight of the bird as they would do if they were solid. Greater strength is also obtained by the cylindrical form of the bone, and a larger surface afforded for the attachment of powerful muscles.