THE ANIMAL KINGDOM. 



107 



peaes"* are birds adapted specially for life in water. 

 Their legs are placed far back on the body, and the toes 

 are united by a membrane called a web, so that the foot 

 becomes a very efficient swimming-paddle. Their plumage 

 is thick, and close to the skin there is a packing of soft 



Fig. 63. 



THE SWAN. 



down ; amongst this, 'oil exudes from the skin, which 

 prevents the water coming into actual contact with their 

 bodies. In some cases the neck is longer than their 

 legs, so that, whilst swimming on the surface of the water,- 

 they can reach their prey, which may be near the bottom. 

 This is seen in the Swan (Fig. 63). 

 Amongst the Natatores we meet with some birds, such 



* Palma, the palm ; pes, the foot. 



