We look at a simple cell and we can see both the world it is embedded in, and the much more limited set of distinctions it is capable of making.  These latter distinctions are drawn in terms of the cell’s own constitution and collectively form the world met by the cell: its phenomenal world.  Now we look at our own P-world.  We can imagine a being with greater perceptual abilities standing above and without all that we see and encounter and seing us in similar fashion.  Where then, is our equivalent to the membrane?  Answer: the limits of perception: those surfaces and sounds and sensations that make up the P-world.  Put differently, the media constitute the membrane of the P-world.  This serves to help define media too.