Sponges: A Bunch of Holes Held Together by Some Cells Sponges: A Bunch of Holes Held Together by Some Cells Sponges: A Bunch of Holes Held Together by Some Cells Sponges: A Bunch of Holes Held Together by Some Cells Sponges: A Bunch of Holes Held Together by Some Cells Sponges: A Bunch of Holes Held Together by Some Cells Sponges: A Bunch of Holes Held Together by Some Cells Sponges: A Bunch of Holes Held Together by Some Cells Sponges: A Bunch of Holes Held Together by Some Cells