Publisher Summary This chapter deals with with the intimate interactions between cells that
appear under the light microscope to be in contact that is, not separated by other cells or by
appreciable fluid spaces. Considerable impetus in this direction has been given by evidence
that in tissue culture both movement and division may be altered by cell contact, the short-
range character of these effects being repeatedly emphasized. Attention has been directed
at several distinct mechanisms of contact interaction: adhesion; exchange of molecules …