226 PHYSICAL BASIS OF CIVILIZATION 



reproduction, except by the co-operation of both 

 sexes, is unheard of, if not absolutely impossible. 



From this brief survey it appears, then, that the 

 process by which time and freedom from disturb- 

 ance have caused like to separate from unlike has 

 been acting on reproductive substance of all life 

 as a whole ever since life began; reproductive 

 substance originally being distributed homogene- 

 ously throughout the mass of protoplasmic com- 

 pounds. In the next stage, reproductive substance 

 is found distributed throughout the single-celled 

 or multicelled organism, when reproduction by 

 fission took place. In the next step, the repro- 

 ductive substance begins to become somewhat more 

 concentrated in certain portions of the individual, 

 a part of such portion is then extruded and begins 

 building up a new individual. This is gemmation. 

 Next in order, reproductive matter begins to segre- 

 gate into two different substances, each with separate 

 qualities and functions, both of which are located in 

 separate parts of the same individual, but have to 

 unite to reproduce. 



Next in order, neither the whole of the male or 

 female reproductive substances is contained in the 

 same individual; but although the male part of it 

 and its organ have separate existence, they are al- 

 most all there is of the male individual, while the 

 female individual comes nearest being a representa- 

 tive of the species, race, or variety. While at this 

 stage there has been progress in dissociation, 



