True spatial periodicity in vital-protoplasm, that is, in the organismic mega-molecule, [such a molecule] as an extreme example of asymmetry [anyhow], probably is a very subordinated form of periodicity, for the building-block-combinatory ability directly "seduces" (combinatorically-statistically with the restraint of function preservation) to avoid strict repetitions. Metamerization [the sequential repetition, along the longitudinal axis, of body sections, metamers in this case], the most secure foundation for periodic repetition, as a rule, and probably already in the subcellular domain, relates to already too large regions to support [in the sense of : to be] a micro-physical period-harmony in the sense of crystalline order. Moreover, every metamerization is threatened and also certainly followed by an asymmetric differentiation [Such as in adult insects : head - thorax - abdomen] ( local enrichment of functional structures in the sense of increased power of performance), the absolute enemy of continuous periodic order [i.e. subsequent differentiation of the initial metamers stops them to be true metamers.].