PLATE 2 



EXPLANATION OF FIGURES 



I to 10 Successive stages of ring formation by bending in a third chromosome. 



II The three small chromosomes which can be recognized in later prophases of 

 the first division. 



12 to 13 Two stages of ring formation in the small chromosomes shown in 11. 

 14 to 15 Two stages in chromosome formation in these same small chromosomes 

 without ring formation. 



16 to 18 Stages of ring formation by bending in another chromosome. 



19 Early prophase of the first spermatocyte division showing the presence of 

 an elongated chromosome in which are two oval bodies. These serve as recognition 

 marks. 



20 to 24 Stages of ring formation in the chromosome shown in 19. In 20 it is 

 joined end to end to another chromosome. 



26 to 27 Two stages showing that the above chromosome (19) may condense 

 into a bivalent without passing through the ring stage. 



584 



