Earlier work has shown that tissue cultures covering large areas can be grown using a plane substrate of perforated cellophane as a support for the cells (1). As a later development of this work, it was found that by planting cultures from cell suspensions, luxuriant sheets of cells can also be obtained using only the pyrex glass surf ace of the flask as a substrate for the cells (2). In these cellophane or glass-surface substrate cultures, the cells are adherent to the surface of the substrate and form a thin film on its surf ace.

These plane-surface substrate methods of culture have allowed the growth of much larger areas and quantities of cells than have been practical when the cells were grown in a thin layer of plasma gel; however, the question has arisen whether or not the plane-surface substrate could be substituted by some type of fabricated three-dimensional substrate, to the surfaces of which the cells might attach, and through the interstices of which a nutrient fluid might be circulated. In a preliminary exploration of this problem, two general types of substrates have been studied. The first consisted of sheets of perforated cellophane so folded as to provide a large surface, lying in three dimensions, for anchorage of the cells. The second consisted of a mass of fabricated glass particles shaped so that they presented large areas of surf ace to which the cells could attach, and yet shaped so that they allowed free passage of fluid and gas through the matrix mass. In the present paper the proliferation of mouse cells in cultures containing these three-dimensional substrates is reported.