Select Search ----- All Bartleby.com ----- All Reference ----- Columbia Encyclopedia World History Encyclopedia Cultural Literacy World Factbook Columbia Gazetteer American Heritage Coll. Dictionary Roget's Thesauri Roget's II: Thesaurus Roget's Int'l Thesaurus Quotations Bartlett's Quotations Columbia Quotations Simpson's Quotations Respectfully Quoted English Usage Modern Usage American English Fowler's King's English Strunk's Style Mencken's Language Cambridge History The King James Bible Oxford Shakespeare Gray's Anatomy Farmer's Cookbook Post's Etiquette Brewer's Phrase & Fable Bulfinch's Mythology Frazer's Golden Bough ----- All Verse ----- Anthologies Dickinson, E. Eliot, T.S. Frost, R. Hopkins, G.M. Keats, J. Lawrence, D.H. Masters, E.L. Sandburg, C. Sassoon, S. Whitman, W. Wordsworth, W. Yeats, W.B. ----- All Nonfiction ----- Harvard Classics American Essays Einstein's Relativity Grant, U.S. Roosevelt, T. Wells's History Presidential Inaugurals ----- All Fiction ----- Shelf of Fiction Ghost Stories Short Stories Shaw, G.B. Stein, G. Stevenson, R.L. Wells, H.G. Reference > Columbia Encyclopedia   PREVIOUS NEXT   CONTENTS · INDEX · GUIDE · BIBLIOGRAPHIC RECORD The Columbia Encyclopedia, Sixth Edition.  2001-07.   pond scum     accumulation of floating green algae on the surface of stagnant or slowly moving waters, such as ponds and reservoirs. One of the commonest forms is Spirogyra.     The Columbia Encyclopedia, Sixth Edition. Copyright © 2007 Columbia University Press. CONTENTS · INDEX · GUIDE · BIBLIOGRAPHIC RECORD   PREVIOUS NEXT     Click here to shop the Bartleby Bookstore. Welcome · Press · Advertising · Linking · Terms of Use · © 2008 Bartleby.com