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D. D. WHITNEY. 



different from the development of the normal spermatid cells. 

 After the early stage is passed the chromatin material increases 

 in bulk very slightly and becomes composed of coarse granules 



FIG. 2. Brachionus midleri. A, early stage in the development of the rudimen- 

 tary spermatozoon showing the chromatin in the nucleus. This cell is from the 

 same male as the normal spermatid of Fig. i, A, and is of the same age. B, a 

 later stage showing the tail wrinkled and distorted by the fixing fluid; C, last stage 

 showing the stiff and rigid tail attached to the head which contains the chromatin; 

 D, the stiff tail forced through the chromatin to the opposite side of the head by 

 pressure under the cover glass; E, the stiff tail forced through the opposite wall of 

 the head by pressure under the cover glass; F, the stiff tail detached from the head. 

 (Drawn to same scale as Fig. i.) 



