Definition of "euglena" []

• Any of various minute single-celled freshwater organisms of the genus Euglena, characterized by the presence of chlorophyll, a reddish eyespot, and a single anterior flagellum. (noun)

American Heritage(R) Dictionary of the English Language, Fifth Edition. Copyright (c) 2011 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

• "The euglena is a protist and is one of the longer looking cells."
• "Close to the middle of the front of the euglena is a long skinny whip like structure called the flagellum which comes out of the organ called the mouth."
• "For example purposeful behavior surely occurred in unicellular eukaryotic ancestors of modern organisms like paramecia and euglena who perform rather complex adaptive movements."