Sponge
Sponges are animals of the phylum Porifera ( /pɒˈrɪfərə/; meaning "pore bearer"). They are multicellular organisms which have bodies full of pores and channels allowing water to circulate through them, consisting of jelly-like mesohyl sandwiched between two thin layers of cells. Sponges have unspecialized cells that can transform into other types and which often migrate between the main cell layers and the mesohyl in the process. Sponges do not have nervous, digestive or circulatory systems. Instead, most rely on maintaining a constant water flow through their bodies to obtain food, oxygen and remove wastes.
Read more about Sponge: Overview, Distinguishing Features, Classes, Taxonomy
Famous quotes containing the word sponge:
“He who has been impoverished for a long time ... who has long stood before the door of the mighty in darkness and begged for alms, has filled his heart with bitterness so that it resembles a sponge full of gall; he knows about the injustice and folly of all human action and sometimes his lips tremble with rage and a stifled scream.”
—Stefan Zweig (18811942)
“Alas for the affairs of men! When they are fortunate you might compare them to a shadow; and if they are unfortunate, a wet sponge with one dash wipes the picture away.”
—Aeschylus (525–456 B.C.)