Just to add what I 'read' today in "DNA"....regarding cysts:
Not word for word, but from memory, he was discussing agrobacteria and what Monsanto, etc. are doing to eliminate pests through bio-engineered plants which have the natural bacterial pesticides incorporated inside their dna which he says will eliminate all that pollution from the air.
He spoke of the process by which bacteria (parasites) use plants for hosts and how they take over the dna in a cyclical manner in which the reproduction of food and organisms are reproduced in a self contained 'gall' which is actually a cyst....in the stem or in the leaves. That way they have an abundance of nutrients and can live there forever. This is what I believe is the purpose of all cysts in animals, including humans.
Kritts