, . It 



j Shorthorn Longhom Gnu Brahman Yak Bison Musk-ox 



{ (Europe and (South (India) (Tibet) (North (Greenland 



North America) Africa) America) and Canada) 



THE FAMILIAR AND THE STRANGE 



Cowlike animals found in various parts of the world are all alike in some ways. But 

 the strangers differ from the cow and also from one another 



answer is a name, that is a sycamore tree; that is a ruby. Sorting and nam- 

 ing are, of course, very important to us, especially while we are growing up 

 and constantly coming across strange new objects. But the task is endless, 

 for there are a million or more distinct kinds of animals and probably as 

 many kinds of plants. There are numerous varieties of apples or wheat, 

 hundreds of species of beetles and clams. It is impossible for anybody to 

 "know all the kinds of living things". How many different kinds of oak 

 trees can you distinguish, or dogs, or butterflies, or roses? Classifying and 

 naming plants and animals occupy large numbers of men and women the 

 world over. This branch of biology is called taxonomy, from a Greek word 

 meaning "arrangement" or "order". 



Other common questions about living things have to do with the use 

 we can make of them, or with the harm they may do. But to answer such 

 questions about the economics of plants and animals, we must be able to 

 distinguish the various kinds. The logwood tree, a relative of the locust tree 

 living in semitropical regions, was formerly the chief source of black dye. 

 But shiploads of "logwood" came to market with none of the essential 

 pigment-producing materials: the "real" logwood and the not-quite-the- 

 same logwood were not easily distinguishable. 



We commonly recognize familiar species of plants and animals by their 

 general forms, sometimes relying upon surface patterns or coloring. But 

 that raises special problems. For example, is a worm to be considered a 

 small snake, or a snake a large worm? Is the whale a kind of fish? Is 

 moss a kind of grass? 



The more closely we examine and compare plants and animals, the 

 more satisfactorily can we arrange them or sort them. But then we raise new 

 problems. For example, we notice that the arms of a man "correspond" in 

 some way to the forelegs of a horse or a squirrel, and also to the wings of a 

 bird; yet the wings of a bird and those of a butterfly do not correspond in 

 the same way, although they do the same kind of work, 



7 



