Demospongiae are comprised of cells organised into two types of tissues referred to as epitheloid and connective tissues,which are in 3 distinct layers. The epithelial cells surround the body and aquiferous system forming a pinacoderm covering the outer side of the body and incurrent excurrent canals , and flagellated choanoderm forming the lining of the choanocyte chambers (Muller & Text).  Connective tissue lies between this layer reffered to as the mesohyl, which contains the muscle cells allowing contraction. One of the many cells found within the mesohyl are the archeocytes, which are totipotent being able to differentiate into any cell (Ruppert, Fox & Barnes 2004). The existence of cell layers allows the cells to have proliferation, also referred to as cell growth (Muller 2006).