“…Evidence has been presented (36, 37), from histological techniques in conjunction with pH changes and dehydration, that the interfibrillar material is membranous in nature and that the collagen bundles are held together by an amorphous cementing substance which is modified by trypsin (34,35). From these characteristics, Day deduced that, in the ground substance, pro tein with an isoelectric point about 4.5 is present which, when modified, -loses its physical properties (38,39,41). An hyaluronidase-sensitive muco polysaccharide, by its macromolecular properties, may act as a "waterproof ing" of the connective tissue (40) which in essence is a fabric of protein fibers.…”