242 FRANK A. HARTMAN. 



PLATE I. 



FIG. i. A giant secondary spermatogonium containing about forty-six chro- 

 mosomes. 



FIG. 2. An abnormal first spermatocyte with twenty-nine chromosomes. 



FIG. 3. Chromosomes from a single first spermatocyte during anaphase. 

 The cell of this figure and the cell represented in the succeeding plate were so large 

 that they were each cut into four pieces in the process of sectioning. Fifty-four 

 chromosomes toward one pole, forty-nine toward the other. 



