books.google.co.uk - Flagella-dependent motility is widespread throughout prokaryotes and is advantageous when nutrients are limited as a mechanism to migrate to more favorable environments and to compete with other micro-organisms. Flagella systems can also play an important role in additional processes, such as adhesion...http://books.google.co.uk/books/about/Pili_and_Flagella.html?id=UVta7XZJHKYC&utm_source=gb-gplus-sharePili and Flagella
