40 THE PLANT: A GENERAL EXTERNAL VIEW 



bodies, just as you see many kinds of houses in which men 

 live. In appearance they are very different, but in general 

 purpose they are all alike. 



Nutrition and Reproduction. — Every living thing has 

 two great tasks to perform. If any kind of living thing 

 fails to perform these two great tasks, and perform them 

 well, that kind soon disappears from the face of the 

 earth. One of these tasks is to maintain the life of the 

 individual, and, to perform this task, food and air and water 

 are among the things necessary to all living creatures. 

 This task is what we call nutrition. The other great task 

 is to maintain the life of the race, and it we call reproduc- 

 tion. These, then, are the two great and fundamental 

 similarities of all living things — they must keep them- 

 selves alive and, by means of reproduction, they must 

 keep their kind alive. The many kinds of living things all 

 differ more or less from each other in the ways in which 

 they solve these two great life problems, but the problems 

 themselves are the same for all, and in the ways in which 

 they are solved you will find that there is more of sim- 

 ilarity than there is of difference. From the most 

 powerful man to the lowest plant, the life of all of us is 

 determined by the fulfillment of the laws of nutrition and 

 of reproduction more than by anything else. These are 

 the fundamentals of life. They cannot be omitted. 

 All other things are built upon them. They are the 

 foundation. 



14. Nutrition. — By nutrition we mean all that has to 

 do with the maintenance of the life, of the individual. It is 

 something that you already know a good deal about. At 

 least, you have had a good deal of experience with it. 



