238 FRANK A. HARTMAN. 



PLATE IV. 



FIGS. 68 to 74. Stages in the development of a single chromosome (r) during 

 first spermatocyte prophase. The stain had been removed from all of the other 

 chromosomes except the accessory. 



FIGS. 75 to 82. Granules of the corresponding chromosome from other cells 

 of the same animal. 



Fig. 75. All granules divided. 



Figs. 71 and 72. Granules in the process of fusion. 



The granules vary in size and number at similar stages. 



FIGS. 85, 89, 90 and 91. First spermatocytes, showing chromosomes (a) dividing 

 unequally. 



FIGS. 86, 87 and 88. Other examples from the same stage, those in 88 being 

 from the same cell. 



FIGS. 83 and 84. Second spermatocytes, showing chromosomes dividing un- 

 equally. 



