COSMIC PHILOSOPHY 



in this sub-kingdom. The reason why Von Baer 

 overlooked this essential process is probably to 

 be found in the fact that each secondary inte- 

 gration, resulting in increased definiteness, serves 

 to make the accompanying differentiation still 

 more prominent. The differentiation of lungs, 

 for instance, from the outer coat of the endo- 

 derm, becomes marked in proportion as the 

 flower-like buds become integrated into organs 

 of definite contour. But while the two correla- 

 tive processes go on hand in hand, it is none 

 the less true that they are distinct processes, 

 and that a comprehensive formula of evolution 

 must explicitly describe them both. 



In further illustration of this twofold aspect 

 of evolution, we may cite a fact which will by 

 and by be seen to have other important bear- 

 ings, but which may here serve as a valuable 

 appendix to the foregoing discussion. This is 

 the fact that, in ranking different organisms as 

 high or low in the scale of life, we always pro- 

 ceed chiefly with reference to the degree of 

 heterogeneity, definiteness, and coherence which 

 they exhibit. Those plants and animals which 

 we rank as lowest in the scale are simply cells, 

 like the homogeneous cells from which higher 

 plants and animals are developed. So little spe- 

 cialized are these forms that they do not exhibit 

 even those characteristics by which we ordinarily 

 distinguish between vegetal and animal life. As 

 236 



