THE VERTEBRATE ANIMALS 



299 



are evidently for protection against cold and wet, but later in life 

 they serve other uses. The feathers of most male birds are 

 brightly colored. This seems to make them attractive to the 

 females of the species ; thus the male ma^- win its mate. 



Adaptations in the Lower Limbs. — The ankle of a bird is extremely 

 long and reptile-like. Scales are found on the ankle and foot. The 

 most extraordinary adaptations are found in the feet of various 

 birds. Some have the foot adapted to perching, others for swim- 



Adaptations in the feet of birds. Explain, after reading the paragraph on adapta- 

 tion in the lower limbs, how each of the above feet is fitted to do its work. 

 From photograph loaned by the American Museum of Natural History. 



ming, others wading, etc. We are able, by looking at the feet of a 

 bird, to decide almost certainly its habitat, method of life, and per- 

 haps its food. 



In the perching birds we find three toes in front and one behind, 

 the hind toe playing an important part in holding the foot in place. 

 In swallows, rapid and untiring flyers, the feet are small. In the 

 case of the parrots, where the foot is used for holding food, climbing, 

 and clinging, we find the four-clawed toes arranged two in front and 



