The Audubon Societies 397 



JUNIOR AUDUBON WORK 



For Teachers and Pupils 



Exercise XXIII. Correlated Studies: Drawing, Spelling and Clay 



Modeling 



A BIRD'S SKELETON 



This is a large subject to discuss briefly. It is a subject that properly 

 belongs to college or university biology. Many men famous in the field of 

 zoology and comparative anatomy have devoted much time to studying the 

 bird's skeleton and comparing it with the skeletons of other vertebrates. There 

 are a few points, however, which everyone might well know, and probably 

 would enjoy knowing, about the skeleton of a bird. 



Before taking up these points, let us once more state the meaning of the 

 word vertebrate, and with it define biology, zoology, and comparative anatomy. 

 In this way we may be sure that we know exactly about what we are talking. 



A vertebrate, you may recall, is an animal that has a tubular nerve- 

 cord usually encased in a bony frame- work, called the spine or backbone, 

 because it runs along the back of the animal, never more than two pairs of 

 limbs, and whose heart is always on the front side of its body. 



Birds are vertebrates, and not only birds, but also fishes, a great variety 

 of four-footed animals, such as horses, cows, elephants, monkeys, tigers and 

 deer, and the two-legged and two-armed animals, most of which are men. When 

 we study nature in general, we learn all these different creatures by name, and 

 that is quite enough to do at first, though many boys and girls observe a great 

 many other things of interest, all of which we put together and call 

 nature-study. 



As we study nature year after year, we grow more and more curious to 

 know what things are, why they grow and thrive where they do, and what the 

 reasons are for their peculiar forms, habits and uses. Biology, which is a study 

 of all living things, or 'a science of life,' as someone has called it, shows us 

 how to find out some of these matters by examining all we see more carefully. 

 Zoology is a study of animals taken by themselves, and goes with botany, the 

 study of plants. These two studies taken together, you see, are equivalent to 

 biology. Comparative anatomy is a different kind of study. It is really a 

 method of studying what we may call the machinery of animals and plants by 

 means of takmg their different parts one by one and seeing how they are put 

 together and for what purpose. It helps us to discover the true answers to 

 many of the questions in nature-study, biology, zoology and botany. Thus the 

 comparative anatomist is able to tell us why birds can fly, why snakes must 

 crawl, why fishes are better fitted to swim than to walk, why plants in general 

 do little else than to grow and store up food, and many more facts of value. 



