This is a sandwich material, having a spongy layer bonded between two very thin solid layers.

It is a soft spongy layer of living cells, some of which are arranged end to end to form tubes.

He used up an entire cartridge just burying that in a spongy layer of webbing.

The most important are the spongy layer and the compact layer.

Its cells contain many more chloroplasts than the spongy layer.

Beneath the palisade layer is the spongy layer.

The cells of the spongy layer are more rounded and not so tightly packed.

Oligochaetes are also abundant in areas supporting porous and spongy layers of algal mat.

A spongy layer of dead leaves smelled damp and moldy.

It had a thin, tough outer shell under which was an equally tough but spongy and resilient white layer, like tree rubber.