CHAPTER TWO. 

 WHAT DO WE MEAN BY REPRODUCTION? 



1. The Individual; Its Upbuilding and Fate. In Chapter 

 One you saw the course of life in the individual. This course 

 includes a small start, an increase, a period of maturity, 

 a decline, and in the end death. This is so universal that 

 we come to take it for granted; and we forget to inquire 

 why it is so. We want now to see a little more closely 

 how the individual behaves in this circle. 



In most cases the start is more modest than was 

 pictured above. Most individuals really start life as a 

 single cell, which is usually scarcely large enough to be 

 seen with the naked eye. This is true even of some of 

 the very largest plants and animals. We think of the oak 

 as starting in an acorn; but really the acorn is not the 

 beginning. The acorn already contains a young oak. 

 The beginning of the new individual was a single cell 

 back in the tissues of the parent tree. From the fate of 

 this cell it is clear that the power of growth and 

 development must be something marvelous. How cr.n a 

 man or a whale or an oak, with billions of cells and 

 weighing many pounds, come from such small beginnings? 



At the bottom of the whole question is the power of 

 the living individual to take up water and other substances, 

 which we call by the general name foods. This power 

 you are quite familiar with, even if you do not understand 

 it. The organism so changes foods and combines them as 

 to make new living matter like that of the living object 



