9. The bill of the Woodpecker may be compared to the adze which the Carpenter uses for chipping beams of wood. It is only by means of hard blows that this bird can get at the worms which it finds in decaying wood.
10. The Duck’s bill, on the other hand, is flat toothed at the side, exactly formed for straining the food which it gets out of the water.
11. The bill of the Gull is so formed that it can easily take up food from the surface of the water. Where Gulls arrive in large flocks, they eagerly follow the plough in the fields, and are then of great benefit.
12. The bill of the Crossbill is a valuable tool, with which he is able to pick out the seeds from between the scales of the fir cones.
13. The Ortolan splits hard seeds with the arch and the notch in its beak, as it were with nut-crackers.
14. The bill of the Avocet is in shape the opposite of the Curlew,—that of the former curving upwards, of the latter downwards.