Isidore Gersh

The Nature of Ground Substance of Connective Tissue

In 1949 we proposed a relatively simple hypothesis concerning the nature of the ground substance of connective tissue. Since then we have continued working on this problem independently along different lines. One of us (H. R. C.) with his colleagues has been working with electrometrical and chemical methods toward a better understanding of ground substance as a whole, considered as a physicochemical system. The other (I. G.) with his students has aimed at getting a closer view of the submicroscopic structure and relations of ground substance with the electron microscope. Now after ten years, our separate paths have converged. We feel that it may be profitable to attempt to integrate our newer findings with the earlier ones in order to develop, extend, and remodel the original hypothesis. The emphasis in this essay is placed on presenting a unified point of view, insofar as possible, which extends through our actual findings, interpretations, and speculations. Only enough data are given to clarify this point of view, and the references to the original literature are accordingly limited. Many others could readily be cited, for and against the point of view we hold, and numerous other references could be collected in support ofother outlooks. In other words, this essay is designed to emphasize one particular way of looking at certain problems centering around the role of the ground substance of connective tissues; it is not intended as a summary of the literature in the field. Ten years ago we considered the ground substance of connective tissue to be the non-fibrillar, optically homogeneous, extra(or inter-) cellular material (1). This was stainable under certain conditions in sections with the periodic acid leukofuchsin stain (PAS) or metachromatically with