42 Dynamic Evolution 



work it is necessary to perform in restoring 

 the energy lost by dissipation during gesta- 

 tion and early infancy, can be determined 

 only by an investigation of the facts. Our 

 present knowledge is not sufficient for us to 

 reach it by theory. What effect the expendi- 

 ture of energy in growth may have upon the 

 dissipation or accumulation of energy capable 

 of being used to perform outside work, is a 

 refinement not gone into because there are 

 too many opportunities for making unwar- 

 ranted statements. Besides, as it is quite 

 possible to determine the general facts with- 

 out considering this point, there is no reason 

 why we should add this complexity to an 

 already complex problem. 



In animals generally there is a tendency 

 for characters (not necessarily secondary 

 sexual) to develop at certain ages in in- 

 dividuals of successive generations. This 

 tendency for a character to develop at the 

 same age in each generation, appears to be 

 associated with the growth of the individuals. 

 In the absence of precise information to the 



