CONTENTS 



Cicncric Reconibinarion in l^acrcrial \ iruses N. \^iscoNri 1 



Sex in Bacteria: Genetic Studies, 1945-1952 



Joshua Lederberg and E. L. Tatum 12 



Sex in Bacteria: Evidence from Morphology 



W. G. Hutchinson and Henry Spempen 29 



Life Cycles, Sexuality, and Sexual Mechanisms in the Fungi 



John R. Raper 42 



Sexual Reproduction in Diatoms Ruth Pairick 82 



Sex in Unicellular Algae Ralph A. Lewin 100 



Sex in Protozoa: A Comparative Review D. H. Wenrich 1 34 



Mating Type Determination in Faramechnn aurelia: A Study 

 in Cellular Heredity DAvm L. Nanney 266 



Mating Substances and the Physiology of Fertilization in 

 Cihates Charles B, Meiz 284 



Comments on the Origin and Evolution of "Sex" 



D. H. Wenrich 335 



Author Index 347 



Subject Index 354 



