List of Illustrations 9 



FIGTTBB PAGE 



47. REDUCTION OF THE NUMBER OF CHROMOSOMES AT CONJUGATION IN 

 DIDINIUM NASUTUM 178 



48. CONJUGATION AND REDUCTION IN THE NUMBER OF CHROMOSOMES 



IN THE INFUSORIAN ANOPLOPHRYA BRANCHIARUM 180 



49. THE CHROMOSOMES AND THE DIVISIONS PREPARATORY TO MATING 



IN PARAMECIUM CAUDATUM 182 



50. REDUCTION OF THE NUMBER OF CHROMOSOMES BEFORE MATING IN 



THE RHIZOPOD PELOMYXA 183 



51. DIAGRAM TO ILLUSTRATE How MENDELIAN INHERITANCE WOULD 

 OCCUR IN AN INFUSORIAN (PARAMECIUM) 189 



52. CONJUGANTS AND NON-CONJUGANTS FROM A CULTURE COMPOSED OF 

 A MIXTURE OF Two RACES OF DIFFERENT SIZE, OF PARAMECIUM 



AURELIA 191 



.53. PAIRS FROM A SINGLE RACE OF PARAMECIUM AURELIA, ILLUSTRATING 



ASSORTATIVE MATING 192 



