THE LIVING MACHINE BUILDING FACTORS. 151 



the parent from which they sprung. This is the 

 essence of what is called heredity. Its signifi- 

 cance in the process of machine building is evi- 

 dent at once. It is the conserving force which 

 preserves the forms already produced and makes 

 it possible for each generation to build upon the 

 structures of the earlier ones. Without it each 

 generation would have to begin anew at the be- 

 ginning, and nothing could be accomplished. But 

 since this principle brings each individual to the 

 same place where its parents stand, and thus 

 always builds the offspring into a machine like 

 the parent, it makes it possible for the successive 

 generations to advance. Heredity is thus like the 

 power of memory, or better still, like the invention 

 of printing in the development of civilization. It 

 is a record of past achievements. By means of 

 printing each age is enabled to benefit by the dis- 

 coveries of the previous age, and without it the 

 development of civilization would be impossible. 

 In the same way heredity enables each generation 

 to benefit by the achievements of its ancestors in 

 the process of machine building, and thus to de- 

 vote its own energies to advancement. 



The fact of heredity is patent enough. It has 

 been always clearly recognized that the child has 

 the characters of its parents, and this belief is so 

 well attested as to need no proof. It is still a 

 question as to just what characters may be in- 

 herited, and what influences may affect the inher- 

 itance. There are plenty of puzzling problems 

 connected with heredity, but the fact of heredity 

 is one of the foundation stones of biological 

 science. Upon it must be built all theories which 

 look toward the explanation of the origin of the 

 living machine, 

 ii 



