This study is devoted to multicellular aspects of bacterial life. It shows how bacteria are sentient, interactive organisms with a broad repertoire of chemical and physical mechanisms for signalling each other and organizing themselves into multicellular aggregates with novel properties.

PART I: Conceptual Developments. 1: M. Dworkin: Multiculturalism vs. the single microbe,. 2: J.A. Shapiro: Multicellularity is the rule, not the exception: Lessons from E. coli colonies,. PART II: Intercellular Communication. 3: R.E. Ruhfel, B.A.B. Leonard, and G.M. Dunny: Pheromone-inducible conjugation in Enterococcus faecalis: mating interactions mediated by chemical signals and direct contact,. 4: P.V. Dunlap: N-acyl-L-homoserine lactone autoinducers in bacteria: unity and diversity expanding the prokaryotic paradigm: E. coli colonies teach us that multicellularity is the rule rather than the exception,. PART III: Multicellular Lifestyles. 5: D.G. Adams: Cyanobacteria,. 6: K.F. Chater and R. Losick: The mycelial life-style of Streptomyces Coelicolor A3(2) and its relatives,. 7: R. Belas: Proteus mirabilis and other swarming bacteria,. 8: L.J. Shimkets and M. Dworkin: Myxobacterial multicellularity,. 9: P.E. Kohlenbrander: Oral microbiology and coaggregation,. PART IV: Examining Multicellular Populations. 10: B. Hauer abd H. Eipel: Flow cytometry: a useful tool for analyzing bacterial populations cell by cell,. 11: N.K. Fry, L. Raskin, R. Sharp, E.W. Alm, B.K. Mobarry, and D.A Stahl: In situ analyses of microbial populations with molecular probes: the phylogenetic dimension,. PART V: A More Physical View of Bacterial Multicellularity. 12: N.H. Mendelson, B. Salhi, and C. Li: Physical and Genetic consequences of multicellularity in Bacillus subtilis,. 13: M. Matsushita: The formulation of colony patterns by a bacterial cell population,. 14: E. Ben-Jacob and I. Cohen: Cooperative formation of bacterial patterns,. 15: J.O Kessler and M.F. Wojciechowski: The collective behavior and dynamics of swimming bacteria,