M-185 is a state trunkline highway in the US state of Michigan that circles Mackinac Island, a popular tourist destination. A narrow paved road of 8.004 miles (12.881 km), it offers scenic views of the Straits of Mackinac dividing the Upper and the Lower peninsulas of Michigan, Lake Huron, and Lake Michigan. It has no connection to any other state highways and is accessible only by passenger ferry. M-185 passes several key sites within Mackinac Island State Park, including Fort Mackinac, Arch Rock, British Landing, and Devil's Kitchen. Outside of the downtown area, it runs between the water's edge and woodlands. Traffic on is by foot, on horse, by horse-drawn vehicle, or by bicycle; motorized vehicles have been banned since the 1890s, and only a few vehicles have been permitted on the island other than emergency vehicles. It is the only state highway in the US where cars cannot drive. The highway was built during the first decade of the 20th century by the state and designated as a state highway in 1933. It was paved in the 1950s, and portions were rebuilt to deal with shoreline erosion in the 1980s. Until 2005, it was the only state highway without any automobile accidents. (Full article...)
A cross section of a post-clitellum segment of an annelid (ringed worm); almost all segments of an annelid contain the same set of organs and parts, a pattern called metamerism. Annelids have no lungs, but rather exchange carbon dioxide and oxygen directly through the moist skin when blood reaches the extremely fine capillaries of the body walls; a dry worm cannot breathe and will die of suffocation. The worm's red blood, which does not consist of platelets or red cells but mostly of a liquid containing suspended hemoglobin, makes a circuit up and down the animal in its closed circulatory systems.