On the Origin of the Connective-tissue Ground-substance in the Chick Embryo

ABSTRACT Szily (26) demonstrated in the early development of. the chick embryo, as well as in certain other species, a cell-free, fibrous, connective-tissue ground-substance which was quite generally present, filling the various cavities of the embryonic body. This investigator was of the opinion that this material was intracellular in its origin, arising, as he believed, by a transformation of cell processes from any of the surrounding cells, without regard to the particular germ-layer to which they belonged, but previous to the advent of the mesenchyme cells.