Membrane
an expansion of any tissues in a thin and wide layer. Bichat divides them into serous, mucous, and fibrous membranes. Among the most important membranes in the body are those of the brain: viz., the dura mater, the arachnoid, the pia mater and the falx.
Undulating membranes, simple membranous bands, one margin only of which is attached, the other being free and exhibiting an undulatory motion. They are allied to and answer the same purpose as cilia. They are stated to occur on the spermatozoa of salamanders and tritons, and in the water vessels of some Annelids, Infusoria, and Rotatoria. MEMEL (mā'mel), a Prussian seaport, defended by a citadel and two forts on the sea side; at the N. extremity of the Kurisches Haff, at its opening into the MEMPHIS Baltic, 70 miles N. N. E. of Danzig; has a large harbor, and exports from Lithuania and Russia timber, flax and linseed, coal, manure, grain, and herrings; has also manufactories of brandy, soap and chemicals, sawmills, iron foundries, breweries, and shipbuilding yards. Memel was founded in 1252 by the Livonian order, who gave it to the Teutonic Knights, by whom it was fortified in 1404. It suffered severely in the Lithuanian wars (13th to 15th centuries). Here in 1807 Frederick-William III. of Prussia took refuge, and a treaty with England was signed. Having been almost wholly destroyed by fire in 1854, it was rebuilt in modern style. The city was captured by the Russians in 1914, but the German armies soon regained it and retained possession. Pop. about 25,000.