New World Encyclopedia integrates facts with values.
Written by online collaboration with certified experts.
Thoreau was not a systematic philosopher but advanced his thought by embedding his ideas in the context of descriptive narrative prose. He is best known for Walden and Civil Disobedience, but wrote many other articles and essays. He was a lifelong abolitionist and delivered lectures attacking the Fugitive Slave Act, praising the writings of Wendell Phillips, and defending the abolitionist John Brown following Brown's assault on the federal arsenal at Harpers Ferry. Thoreau's Civil Disobedience influenced later nonviolent reformers, particularly Mohandas Gandhi and Martin Luther King, Jr.
Algae range from single-celled organisms to multi-cellular organisms, some with fairly complex differentiated form and, if marine, called seaweeds. Some of the single-celled organisms may be as small as one micrometer. Multicellular algae may consist of a row of cells, appearing as a filament, or as a thin plate of cells, or even some larger ones may have bodies with a rudimentary division of labor. The multicellular giant kelp reaches 60 meters in length. Seaweeds themselves have many forms, including those that appear as if terrestrial plants with leaves and stems, looking like moss, mushrooms, leaf lettuce, or even palm trees.