from wherever we happen to be — which is with ourselves. Indeed, we can- 

 not do otherwise. We "understand" other people as we recognize in their 

 actions our own purposes and motives and interests. When people act in 

 ways very different from our ways, they may amuse us or annoy us, but 

 they also puzzle us. And we try to "understand" other living things, and 

 even nonliving things, by assuming that they have purposes and concerns 

 like ours. 



We enlarge our knowledge by moving away from our starting-point. We 

 compare more and more kinds of living things with ourselves, but also with 

 one another. We compare living things with those that are not alive. We 

 try to find out what the living and the nonliving have to do with each other, 

 how they are related. We try to find out what "life" is by studying its 

 various forms and its ways of acting — and what it means to man, who is 

 still at the center of our universe. By enlarging our knowledge we come 

 slowly to useful understandings, which help us to get along better. 



Original |''?\cell 



:fe^--7(^ 





\-'jy^ Nucleus 



Nucleus elongates ^^^^^ 



THE LIFE OF A SIMPLE ANIMAL 



^/M) 



Two nuclei 

 move apart 



^■^■ 



Two ends 



of cell 

 move apart 



Two distinct 

 cells result 



The ameba has no definite shape, but moves about, pushing its jellylike mass now 

 in one direction, now in another. After an ameba reaches its full growth, the nu- 

 cleus, or kernel, lengthens out and gradually divides into two parts. The rest of the 

 animal's body also lengthens, and the two ends seem to move slowly away from each 

 other until there are two distinct individuals. Each of these is as complete as the 

 other, and both are the same as the original mother cell except for size 



10 



