Flatworms also have a feature that the sponges and cnidarians do not, a middle layer of actual organized cells. Flatworms have three cell layers: an ectoderm, an outer covering like the other groups have; an endoderm, a lining of the digestive spaces somewhat like a cnidarians; and a mesoderm between the other two. With actual tissues protected like this, another evolutionary explosion of features happened.
Buying a home in Fredericktown, PA. Fredericktown is a city in Washington County, Pennsylvania. Last year, 2 properties were sold for a median price of $49,000. Average price for a home in Fredericktown, PA is $49,000. The average property tax is $1,186 per year.
County History. Frederick County was established in 1743 out of Orange County. Frederick Lewis, Prince of Wales and the oldest son of King George II of Great Britain, was the inspiration behind the name. Commander In Chief of the Colonial Forces, General George Washington's headquarters were in Winchester, Washington.