Assertion: sponge's layer | /r/HasProperty | outer
Facets:
Source sentences:
text: Sponges have no nervous systems, their middle jelly-like layers have large and varied populations of cells, and some types of cells in their outer layers may move into the middle layer and change their functions.
text: Their nearly organless bodies consist of just three layers—the outer epidermis, the middle mesoglea, and the inner gastrodermis.