ORIGIN AND NA TURE OF LIFE. 337 



tion. But so far as protoplasm is concerned, so far 

 as there is question of the simplest unicellular moner 

 which the microscopist has yet observed, we can un- 

 hesitatingly say that spontaneous generation is im- 

 possible. We may conceive how simple chemical 

 forces can produce a chemical compound of even the 

 greatest complexity. But we cannot picture to our- 

 selves how such forces, unaided and alone, can pro- 

 duce an intricate organism, such as is even the lowest 

 representative of animate nature. It were as easy to 

 imagine a watch evolving itself spontaneously from 

 the raw material which composes it ; to picture a 

 man-of-war arising spontaneously from the piles of 

 wood and stores of iron and brass in a shipyard. 



If, then, spontaneous generation is not a chimera, 

 it is something which has far humbler beginnings 

 than has ordinarily been supposed. If it ever took 

 place at all, it must have occurred in some homoge- 

 neous chemical compound which was the product of 

 known chemical forces. And if this be true, the 

 time which elapsed from the formation of such a liv- 

 ing compound, until its development into the highly 

 organized protoplasm which we now know, must 

 have embraced as many long aeons as intervened 

 between the advent of protoplasm and the first ap- 

 pearance of the higher orders of animal and plant 

 life. 



The mechanical theory of life, it is thus seen, is 

 far from being borne out by the known facts of 

 science. It assumed the homogeneity of protoplasm ; 

 and in this it was in error. It assumes the origin of 

 life by the action on the elements of forces which 



