EXPLANATION OF PLATE VI 



FIG. 27. X l,ooo. Still later stage. Fusion of chromosome-vesicles more 

 advanced. Several of these have united, leaving part of the chromosomes still in 

 separate vesicles. 



FIG. 28. X 1 ,000. Fusion of the chromosome -vesicles complete, but the nucleus 

 still retains a slight trace of its former vesicular condition. .Nuclei of this shape are^ 

 often to be found until transformation into spermatozoa takes place. All trace o 

 astral rays has disappeared. 



FIG. 29. X l,ooo. All trace of vesicular stage has disappeared from the nucleus. 

 Typical cell at the close of the second spermatocyte division. 



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