In conclusion, it is noteworthy that though resorting to utterly fanciful hypotheses respecting the order of the development of the world, Anaximander agrees with modern evolutionists in conceiving the heavenly bodies as arising out of an aggregation of diffused matter, and in assigning to organic life an origin in the inorganic materials of the primitive earth (pristine mud).
In a few cases both among the higher and the lower plants, of which the formation of spores in the ascus is a typical example, new cells are formed by the aggregation of portions of the cytoplasm around the nuclei which become delimited from the rest of the cell iontents by a membrane.
This aggregation of genera and of endemic species is characteristic of the circumferential portions of the earths land surface: the expansion of the one and the further advance of the other is arrested.
The aggregation of population in towns was at one time mainly brought about by the necessity for defence, a fact indicated by the defensive sites of many old towns.
These tectonic arches often extend for long distances with great regularity, but are frequently crossed by subsidiary anticlines, which themselves play a not unimportant part in the aggregation of the oil.