2 3 o PHYSICAL BASIS OF CIVILIZATION 



attraction and least resistance. Therefore does the 

 excess of force in the fertilized ovum transform and 

 absorb the comparatively inert materials in the 

 environment. Later, when the organism has re- 

 placed the fertilized ovum, then it will, so long as it 

 retains an excess of energy, absorb and assimilate 

 environing materials. But as soon as the condi- 

 tions are reversed the movements and changes 

 begin to tend to the absorption and assimilation of 

 the organism by the environment. 



To any one familiar with the present state of 

 biologic and histologic science, it is obvious that the 

 two substances which by their mixing form the 

 fertilized ovum must be complementary for co-opera- 

 tion with each other in innumerable ways. If 

 either of them falls short in any of the details essen- 

 tial in this multiform complementariness, then there 

 must either result a failure to reproduce or an 

 imperfect reproduct. 



Even if the two substances are fully equal to the 

 requirements of co-operation, yet if the structures, 

 viz., the reproductive organs through and into 

 which they have to pass to become conjugated, are 

 not perfectly adapted in every detail to their trans- 

 mission, retention, and accommodation during the 

 preliminary and embryonic stage, then this may 

 easily result in complete or partial failure of repro- 

 duction, or in a defective reproduct. The failure 

 to reproduce, or the fact of reproducing sterile off- 

 spring, may therefore be explained as the result of 



