True membranes must fit these structural and functional qualifications: consist of a superficial layer of epithelial tissue and a layer of connective tissue on which it rests; and, anchor organs in place, serve as barriers, function in immunity and secrete various substances.

i thinking chemical change

emerging idea only occurs as a raw idea that could appear out of nowhere. meanwhile, to reach scientific consensus , that idea must be structured and tested over and over again through various experiments. the scientific consensus transforms the raw idea into idea that is more reliable through the process of scientific elimination.