I ended up on this page redirected the great microbiology blog of Elio Schaechter - his surprising story about the bacteria-farming Dyctostelium http://schaechter.asmblog.org/schaechter/2011/02/farmer-joe-dictyostelium.html

His is a blog dedicated to all sorts of intricate symbiotic relationships. The microbiological revolution as biology historian Jan Sapp showed in his ground breaking books - redefined some of the most basic assumptions regarding the rise is complex life on earth, taxonomy and evolution. These transformations were spearheaded (as at the spore ladden tip of slime mold sori) by particular totemic non human organisms & the researchers specialising in them. Lichens & lichenologists were responsible for a growing interest in mutualism & symbiotic relations. The origins of multicellular life, of sociality was spurred by J T Bonner - and his micro movies about cellular alone molds and their transitions from lone amoeba - to the light & heat sensing, moving "slug" like colonial stages. Well this is a German TV snippet about his model organism - how it's collected in the field (grows in the soil were out feeds on various soil bacteria), and transported to petri dishes & grown so as to show the metamorphosis that situates it in-between unicellular and multicellular lifeforms.

This liminal status, in btw phases and always reversible - amply demonstrated in this small short movie makes it so important a guide for us - spreading out what traits reserved for so called "higher organisms" (including ourselves).
Small bundles of amoeba (it is a Protista - not a fungus as it's name might imply) flow together, they form a river that becomes a new shape - a body that wasn't before. Now united as with a common purpose, they all(all & one are here unnecessary tags) slide towards new bacteria grazing grounds or were they can elegantly - rise up on a 2mm stalk to produce a spore bearing cap.
Such different, but succesive forms, such heterogeneous manifestations. There are some movies any the secret life of cellular slime molds, but this is one of my favorites. And the End holds some surprise, were you can truly measure the scale of things (as Bonner would have appreciated) with a tiny (but huge in proportion) snail that helps carry (phoresis?) the spores of the slime molds to even farther locations (inside our minds also).