294 



ZOOLOGY 



in man are here in part lost and partly grown together. Scales are found 

 on the ankle and foot; in very early life they resemble feathers, both in 

 appearance and manner of growth. If mounted specimens are obtainable, 

 notice the different feet in different birds. Some have the foot adapted 

 to perching, others for swimming, others wading, etc. Take some one ex- 

 ample and attempt to explain all the devices which serve to adapt the foot 

 to its use. Is there anything in the life of the bird that would make the 

 correlation of the adaptation of the foot for scratching and perching ? Note 

 the method of walking in a sparrow, robin, and pigeon. What is there 

 about the position or structure of the leg that adapts it for walking or hop- 

 ping? In the ostrich and cassowary the wings are not used for flight; 



Explain, after reading the paragraph on adaptation in the lower limbs, how each of the 

 above feet are fitted to do their work. From photograph loaned by the American 

 Museum of Natural History. 



here the lower limbs have taken up the function of rapid motion. Notice 

 any adaptations for aquatic life that you may find, and explain in each case 

 how the part described is fitted for the work to be done. The foot of the 

 common barnyard duck, for example, is much like that of the alligator. 



The Skeleton. — The whole skeleton combines Hghtness, flexi- 

 bihty, and strength. Many of the bones are hollow or have large 

 spongy cavities. The bones of the head and neck show many 

 and varied adaptations to the life that the bird leads. The 

 vertebrae which form the framework of the neck are strong and 



