DUCKS 219 



C. The Food of the Duck is chiefly obtained in the Water. 



It consists of molluscs, worms, aquatic insects and their larvae, 

 occasionally also amphibians and small fish, all kinds of water-plants 

 (" duckweed ") and the animals, spawn of molluscs, etc., attached to 

 them. The bird also visits meadows and fields, and consumes all kinds 

 of seeds and grain, grass and young crops. The tame duck, though fed 

 by its keepers (what with?) nevertheless prefers to find animal food 

 for itself in the water. Aquatic animal life, however, is always more 

 abundant by the banks of a pond or stream, among the reeds, than in 

 the open water, and in shallow pieces of water more so than in deep ones. 

 (Demonstrate this by drawing a net of fine gauze through the water, 

 and then turning out its contents into a vessel of water.) Accordingly, 

 the duck is most frequently met with in places of this description. 



HEAD OF WILD DUCK. 



1. Its long neck enables it to immerse its beak to a fair depth, and 

 to rummage about in the mud at the bottom of shallow pieces of water. 



2. In doing this the bird also immerses the anterior part of the body, 

 and consequently appears as though it " stood on its head." It is 

 enabled to assume this position owing to the centre of gravity of the body 

 being placed far forwards (position of legs), which facilitates the tipping 

 over of the body in a forward direction. 



3. (a) The upper half of the beak is covered with a soft skin, which 

 in front is provided with numerous tactile corpuscles. (The subjacent 

 bones at this portion of the beak are perforated like a sieve, the perfora- 

 tions being traversed by the nerves which terminate in the tactile 

 papilla*.) By the help of this tactile apparatus the duck is able to find 

 its food even in turbid water and in the mud. (Compare with snipe, 

 mole, and bat.) 



15 



