THE LIVING MACHINE BUILDING FACTORS. 133 



History of the Living Machine. In the first 

 place, we must notice that these machines have 

 not been fashioned suddenly or rapidly, but have 

 been the result of a very slow growth. They 

 have had a history extending very far back into 

 the past for a period of years which we can only 

 indefinitely estimate, but certainly reaching into 

 the millions. As we look over this past history 

 in the light of our present knowledge we see that 

 whatever have been the forces which have been 

 concerned in the construction of these machines 

 they have acted very slowly. It has taken cen- 

 turies, and, indeed, thousands of years, to take the 

 successive steps which have been necessary in this 

 construction. Secondly, we notice that the ma- 

 chines have been built up step by step, one fea- 

 ture being added to another with the slowly pro- 

 gressing ages. Thirdly, we notice that in one 

 respect" this construction of the living machine 

 by nature's processes has been different from 

 our ordinary method of building machines. Our 

 method of building puts the parts gradually into 

 place in such a way that until the machine is fin- 

 ished it is incapable of performing its functions. 

 The half-built engine is as useless and as power- 

 less as so much crude iron. Its power of action 

 only appears after the last part is fitted into place 

 and the machine finished. But nature's process 

 in machine building is different. Every step in 

 the process, so far as we can trace it at least, 

 has produced a complete machine. So far back 

 as we can follow this history we find that at 

 every point the machine was so complete as to 

 be always endowed with motion and life activity. 

 Nature's method has been to take simpler types 

 of machines and slowly change them into more 



