DIASTROPHISM AND THE FORMATIVE PROCESSES 127 



study need not, however, go much beyond the conditions that 

 determined the amount and nature of the material, the mode of 

 aggregation, and its physical state. It must be specific enough, 

 however, to touch the conditions that controlled the relative 

 proportions of inherently heavy and inherently light material. It 

 is therefore necessary to consider with some care the basic laws of 

 organization of such bodies so far as these bear on selective segre- 

 gation. It will save time and help toward clear treatment to give 

 at the outset what seem to me to be the more essential principles 

 that control the formation of cosmic bodies. It will not be amiss 

 if these are made rather sweeping, provided they are definite 

 enough to apply to the particulars required by our problem. 



PRELIMINARY CONSIDERATIONS 



While the four bodies named will usually be in mind when 

 other bodies are not specified, there will be occasion to use certain 

 terms in other than their commonest senses, and so let us agree 

 upon these at the outset. By cosmic units let us understand, not 

 simply celestial bodies, but organized bodies of any kind, whether 

 large or small, whether "organic" or "inorganic," provided they 

 serve a unitary function in natural processes. Let us recognize 

 that these range from the atom, whose organization is now being 

 pursued with a skill and success worthy of the highest admiration, 

 up through the molecule, the crystal, the chondrus, the colloidal 

 unit, the cell, the biologic organism, the planet, the star, the star 

 cluster, to the stellar galaxy, at least. Let these more salient 

 types stand for the multitude of intermediary and divergent species 

 of divers sorts that make up the full series. Let them also stand 

 for the unknown extensions of the series downward and upward. 

 Let us agree that the only essential of a cosmic unit is an individual- 

 ized organization which has its own material center and its own 

 dynamic province. These organized units of course enter into 

 varied relations with one another and form a great complex super- 

 series, but let us consider merely the features that are common to 

 all because essential to all. Among these essentials should appear, 

 in their true relations, those particular features we need to apply 

 to the solution of our special problem. 



