Substage 5 is about control of form. In humans (level 1, stage 7 Young), creativity shows itself at work (substage 5). Young puts creative genius in this substage. This genius certainly has an ego (quite an ego, at times). The big transformation of the ego/self is something that occurs in substage 6.
In plants (typifying stage 5), there is, in substage 1 of stage 5 of the Young model, the appearance of the cell. First there is the proto-cell, the prokaryote, sometimes called microbe. Later we get the eukaryote. These microbes of substage 1 seem to play a role in the evolution of the cell, as in endosymbiosis - for example, the mitochondrion in the cell. One of the striking features of stage 5 is the presence and activity of membrane organizers. Negentropy or syntropy is only possible if there is some kind of boundary imposed between a center and its environment. Vesicles play an important role in the cell, something to be studied in more detail.
The phospholipid bilayer forms the plasmamembrane, together with certain classes of proteins.These phospholipids can form rings or other closed structures - very interesting indeed. The double feature of hydrophobic tails and hydrophilic heads is something we must keep in mind. Is this bipolarity reproduced in nature on other levels and scales?
On a more esoteric note, the mind has its own enclosure. "Closedmindedness" is not just a linguistic phrase. The human aura is composed of many layers ("membranes") with pores in it, according to the eminent esoterist De Purucker. I suppose that many people would be very surprised if they would get to know more about the functions of the human aura/consciousness. The projections of the mind are many and varied - a subject shrouded in mystery.