PLATE 2 



EXPLANATION OF FIGURES 



Side view of first spermatocytes from eight individuals of form 'A.' showing 

 variation of complex from individual to individual. 



6 An animal with eight chromosomes of the Stenobothrus type. 



7 A different individual with only four such chromosomes. The other four 

 being replaced by J-shaped tetrads. 



Kir, 



