Figure 39.1 No Cell Too Far The sponge Leucosolenia is a tube about 2 cm. long with an outer and an inner layer of cells and a jelly-like matrix. There are pores between the cells of the tube. The inner cells have flagella that create a current of water in through the pores and out through the opening at the top. The individual cells of this animal can obtain nutrients and oxygen directly from the seawater.