How are sponges' bodies structured?

Sponges come in three different forms or morphologies, including asconoid (simple tubes), syconoid (tubular body with an osculum), and leuconoid (mass full of canals and chambers into and out of which water flows).  Sponges have a multi-cellular make up in which there are cells that serve different functions and are loosely organized in such a manner, but similar cells are not further organized to form tissues.