302 THE HISTORY OF CREATION. 



(for example, an Amoeba, or a single-celled plant), could 

 never perform. 



No sensible person supposes that carefully devised insti- 

 tutions, which have been established for the good of the 

 whole, as well as for the individual, in every human state, 

 are the results of the action of a personal and supernatural 

 Creator, acting for a definite purpose. On the contrary, 

 every one knows that these useful institutions of organiza- 

 tion in the state are the consequences of the co-operation of 

 the individual citizens and tlieir common government, as 

 well as of adaptation to the conditions of existence of the 

 outer world. Just in the same way we must judge of the 

 many-celled organism. In it also all the useful arrangements 

 are solely the natural and necessary result of the co-operation, 

 differentiation, and perfecting of the individual citizens — 

 the cells — and by no means the artificial arrangements of a 

 Creator acting for a definite purpose. If we rightly consider 

 this comparison, and pursue it further, we can distinctly 

 see the perversity of that dualistic conception of nature 

 which discovers the action of a creative plan of construction 

 in the various adaptations of the organization of living 

 things. 



Let us pui'sue the individual development of the verte- 

 brate animal body a few stages further, and see what is next 

 done by the citizens of this embryonic organism. In the 

 central line of the violin-shaped disc, which is composed of 

 the three cellular germ-layers, there arises a straight deli- 

 cate furrow, the so-called " primitive streak," by which the 

 violin-shaped body is divided into two equal lateral halves — 

 a right and a left part or " antimer." On both sides of that 

 streak or furrow, the upper or external germ-layer rises in 



