A glial cell that develops from a Schwann cell precursor. The immature Schwann cell is embedded among neurons (axons) with minimal extracellular spaces separating them from nerve cell membranes and has a basal lamina. Cells can survive without an axon present. Immature Schwann cell can be found communally ensheathing large groups of axons. [ GOC:tfm GOC:cvs http://openisbn.com/search.php?q=0721662544&isbn=1/ ]